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[PATCH v15 3/8] Row pattern recognition patch (rewriter). 107+ messages / 2 participants [nested] [flat]
* [PATCH v15 3/8] Row pattern recognition patch (rewriter). @ 2024-03-28 10:30 Tatsuo Ishii <ishii@postgresql.org> 0 siblings, 0 replies; 107+ messages in thread From: Tatsuo Ishii @ 2024-03-28 10:30 UTC (permalink / raw) --- src/backend/utils/adt/ruleutils.c | 103 ++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index a51717e36c..51ba9fc7b4 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -426,6 +426,10 @@ static void get_rule_groupingset(GroupingSet *gset, List *targetlist, bool omit_parens, deparse_context *context); static void get_rule_orderby(List *orderList, List *targetList, bool force_colno, deparse_context *context); +static void get_rule_pattern(List *patternVariable, List *patternRegexp, + bool force_colno, deparse_context *context); +static void get_rule_define(List *defineClause, List *patternVariables, + bool force_colno, deparse_context *context); static void get_rule_windowclause(Query *query, deparse_context *context); static void get_rule_windowspec(WindowClause *wc, List *targetList, deparse_context *context); @@ -6480,6 +6484,67 @@ get_rule_orderby(List *orderList, List *targetList, } } +/* + * Display a PATTERN clause. + */ +static void +get_rule_pattern(List *patternVariable, List *patternRegexp, + bool force_colno, deparse_context *context) +{ + StringInfo buf = context->buf; + const char *sep; + ListCell *lc_var, + *lc_reg = list_head(patternRegexp); + + sep = ""; + appendStringInfoChar(buf, '('); + foreach(lc_var, patternVariable) + { + char *variable = strVal((String *) lfirst(lc_var)); + char *regexp = NULL; + + if (lc_reg != NULL) + { + regexp = strVal((String *) lfirst(lc_reg)); + + lc_reg = lnext(patternRegexp, lc_reg); + } + + appendStringInfo(buf, "%s%s", sep, variable); + if (regexp !=NULL) + appendStringInfoString(buf, regexp); + + sep = " "; + } + appendStringInfoChar(buf, ')'); +} + +/* + * Display a DEFINE clause. + */ +static void +get_rule_define(List *defineClause, List *patternVariables, + bool force_colno, deparse_context *context) +{ + StringInfo buf = context->buf; + const char *sep; + ListCell *lc_var, + *lc_def; + + sep = " "; + Assert(list_length(patternVariables) == list_length(defineClause)); + + forboth(lc_var, patternVariables, lc_def, defineClause) + { + char *varName = strVal(lfirst(lc_var)); + TargetEntry *te = (TargetEntry *) lfirst(lc_def); + + appendStringInfo(buf, "%s%s AS ", sep, varName); + get_rule_expr((Node *) te->expr, context, false); + sep = ",\n "; + } +} + /* * Display a WINDOW clause. * @@ -6617,6 +6682,44 @@ get_rule_windowspec(WindowClause *wc, List *targetList, appendStringInfoString(buf, "EXCLUDE GROUP "); else if (wc->frameOptions & FRAMEOPTION_EXCLUDE_TIES) appendStringInfoString(buf, "EXCLUDE TIES "); + /* RPR */ + if (wc->rpSkipTo == ST_NEXT_ROW) + appendStringInfoString(buf, + "\n AFTER MATCH SKIP TO NEXT ROW "); + else if (wc->rpSkipTo == ST_PAST_LAST_ROW) + appendStringInfoString(buf, + "\n AFTER MATCH SKIP PAST LAST ROW "); + else if (wc->rpSkipTo == ST_FIRST_VARIABLE) + appendStringInfo(buf, + "\n AFTER MATCH SKIP TO FIRST %s ", + wc->rpSkipVariable); + else if (wc->rpSkipTo == ST_LAST_VARIABLE) + appendStringInfo(buf, + "\n AFTER MATCH SKIP TO LAST %s ", + wc->rpSkipVariable); + else if (wc->rpSkipTo == ST_VARIABLE) + appendStringInfo(buf, + "\n AFTER MATCH SKIP TO %s ", + wc->rpSkipVariable); + + if (wc->initial) + appendStringInfoString(buf, "\n INITIAL"); + + if (wc->patternVariable) + { + appendStringInfoString(buf, "\n PATTERN "); + get_rule_pattern(wc->patternVariable, wc->patternRegexp, + false, context); + } + + if (wc->defineClause) + { + appendStringInfoString(buf, "\n DEFINE\n"); + get_rule_define(wc->defineClause, wc->patternVariable, + false, context); + appendStringInfoChar(buf, ' '); + } + /* we will now have a trailing space; remove it */ buf->len--; } -- 2.25.1 ----Next_Part(Thu_Mar_28_19_59_25_2024_076)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v15-0004-Row-pattern-recognition-patch-planner.patch" ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
* [PATCH v5 10/10] Additional validation for buffer in the ring @ 2025-06-11 12:45 Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 0 siblings, 0 replies; 107+ messages in thread From: Ashutosh Bapat @ 2025-06-11 12:45 UTC (permalink / raw) If the buffer pool has been shrunk, the buffers in the buffer list may not be valid anymore. Modify GetBufferFromRing to check if the buffer is still valid before using it. This makes GetBufferFromRing() a bit more expensive because of additional boolean condition. That may not be expensive enough to affect query performance. The alternative to that is more complex as explained below. The strategy object is created in CurrentMemoryContext and is not available in any global structure thus accessible when processing buffer resizing barriers. We may modify GetAccessStrategy() to register strategy in a global linked list and then arrange to deregister it once it's no more in use. Looking at the places which use GetAccessStrategy(), fixing all those may be some work. Ashutosh Bapat --- src/backend/storage/buffer/freelist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 41641bb3ae6..74d070733a4 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -948,12 +948,13 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state) strategy->current = 0; /* - * If the slot hasn't been filled yet, tell the caller to allocate a new - * buffer with the normal allocation strategy. He will then fill this - * slot by calling AddBufferToRing with the new buffer. + * If the slot hasn't been filled yet or the buffer in the slot has been + * invalidated when buffer pool was shrunk, tell the caller to allocate a new + * buffer with the normal allocation strategy. He will then fill this slot + * by calling AddBufferToRing with the new buffer. */ bufnum = strategy->buffers[strategy->current]; - if (bufnum == InvalidBuffer) + if (bufnum == InvalidBuffer || bufnum > NBuffers) return NULL; /* -- 2.49.0 --bwrlgp6w2ubxykjq-- ^ permalink raw reply [nested|flat] 107+ messages in thread
end of thread, other threads:[~2025-06-11 12:45 UTC | newest] Thread overview: 107+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2024-03-28 10:30 [PATCH v15 3/8] Row pattern recognition patch (rewriter). Tatsuo Ishii <ishii@postgresql.org> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> 2025-06-11 12:45 [PATCH v5 10/10] Additional validation for buffer in the ring Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
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