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[PATCH 09/19] tmp: run tap tests first 107+ messages / 2 participants [nested] [flat]
* [PATCH 09/19] tmp: run tap tests first @ 2022-04-01 04:52 Justin Pryzby <pryzbyj@telsasoft.com> 0 siblings, 0 replies; 107+ messages in thread From: Justin Pryzby @ 2022-04-01 04:52 UTC (permalink / raw) ci-os-only: windows --- .cirrus.yml | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/.cirrus.yml b/.cirrus.yml index ea1f493923a..ff8b138b9d1 100644 --- a/.cirrus.yml +++ b/.cirrus.yml @@ -416,6 +416,11 @@ task: # Installation on windows currently only completely works from src/tools/msvc - cd src/tools/msvc && perl install.pl %CIRRUS_WORKING_DIR%/tmp_install + this_tap_script: | + %T_C% perl src/tools/msvc/vcregress.pl taptest src/interfaces/libpq + test_tap_script: | + %T_C% perl src/tools/msvc/vcregress.pl alltaptests + test_regress_parallel_script: | %T_C% perl src/tools/msvc/vcregress.pl check parallel startcreate_script: | @@ -437,8 +442,6 @@ task: test_ssl_script: | set with_ssl=openssl %T_C% perl src/tools/msvc/vcregress.pl taptest ./src/test/ssl/ - test_tap_script: | - %T_C% perl src/tools/msvc/vcregress.pl alltaptests test_ecpg_script: | rem tries to build additional stuff vcvarsall x64 -- 2.17.1 --Sw7tCqrGA+HQ0/zt Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="0010-vcregress-run-alltaptests-in-parallel.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 -- 2022-04-01 04:52 [PATCH 09/19] tmp: run tap tests first Justin Pryzby <pryzbyj@telsasoft.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> 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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