pg.ddx.io pgsql-hackers@postgresql.org mailing list archive help / color / mirror / Atom feed From: torikoshia <torikoshia@oss.nttdata.com>
To: PostgreSQL-development <pgsql-hackers@postgresql.org>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Georgios Kokolatos <gkokolatos@protonmail.com>
Cc: Kasahara Tatsuhito <kasahara.tatsuhito@gmail.com>
Cc: craig@2ndquadrant.com
Subject: Re: Get memory contexts of an arbitrary backend process
Date: Wed, 17 Mar 2021 22:24:27 +0900
Message-ID: <70ae4b79eb8b0dcf42161c80a00e3f22@oss.nttdata.com> (raw )
In-Reply-To: <bea016ad-d1a7-f01d-a7e8-01106a1de77f@oss.nttdata.com >
References: <0271f440ac77f2a4180e0e56ebd944d1@oss.nttdata.com >
<270ec80dbbebfb5c6f2b9fdd7a7858b5@oss.nttdata.com >
<160502083340.7362.4386116585349115146.pgcf@coridan.postgresql.org >
<064d510f2d33edc37dfd6b8f3b6bd30e@oss.nttdata.com >
<d42d3186-d647-9af4-7c1c-d6ffca8bff40@oss.nttdata.com >
<1685539.1606959410@sss.pgh.pa.us >
<83ff0aff04fffc95cbd1fc1637a0fccc@oss.nttdata.com >
<28e1feb71b94ac9918830bc4a0c1844f@oss.nttdata.com >
<CAP0=ZV+XcPnX+m9ROG07hs=DqwQCOLAojgvYCRogw=bFAv1+Eg@mail.gmail.com >
<9a59401241e9269254e70c8e0ef1cc7a@oss.nttdata.com >
<4ae7b086a5b49fdfec7c1154d6fc7a40@oss.nttdata.com >
<40c1a4b19ad03beacee2642a3cd61c14@oss.nttdata.com >
<9a50371e15e741e295accabc72a41df1@oss.nttdata.com >
<bea016ad-d1a7-f01d-a7e8-01106a1de77f@oss.nttdata.com >
On 2021-03-05 14:22, Fujii Masao wrote:
> On 2021/03/04 18:32, torikoshia wrote:
>> On 2021-01-14 19:11, torikoshia wrote:
>>> Since pg_get_target_backend_memory_contexts() waits to dump memory
>>> and
>>> it could lead dead lock as below.
>>>
>>> - session1
>>> BEGIN; TRUNCATE t;
>>>
>>> - session2
>>> BEGIN; TRUNCATE t; -- wait
>>>
>>> - session1
>>> SELECT * FROM pg_get_target_backend_memory_contexts(<pid of session
>>> 2>); --wait
>>>
>>>
>>> Thanks for notifying me, Fujii-san.
>>>
>>>
>>> Attached v8 patch that prohibited calling the function inside
>>> transactions.
>>
>> Regrettably, this modification could not cope with the advisory lock
>> and
>> I haven't come up with a good way to deal with it.
>>
>> It seems to me that the architecture of the requestor waiting for the
>> dumper leads to this problem and complicates things.
>>
>>
>> Considering the discussion printing backtrace discussion[1], it seems
>> reasonable that the requestor just sends a signal and dumper dumps to
>> the log file.
>
> +1
Thanks!
I remade the patch and introduced a function
pg_print_backend_memory_contexts(PID) which prints the memory contexts
of
the specified PID to elog.
=# SELECT pg_print_backend_memory_contexts(450855);
** log output **
2021-03-17 15:21:01.942 JST [450855] LOG: Printing memory contexts of
PID 450855
2021-03-17 15:21:01.942 JST [450855] LOG: level: 0 TopMemoryContext:
68720 total in 5 blocks; 16312 free (15 chunks); 52408 used
2021-03-17 15:21:01.942 JST [450855] LOG: level: 1 Prepared Queries:
65536 total in 4 blocks; 35088 free (14 chunks); 30448 used
2021-03-17 15:21:01.942 JST [450855] LOG: level: 1 pgstat
TabStatusArray lookup hash table: 8192 total in 1 blocks; 1408 free (0
chunks); 6784 used
..(snip)..
2021-03-17 15:21:01.942 JST [450855] LOG: level: 2 CachedPlanSource:
4096 total in 3 blocks; 680 free (0 chunks); 3416 used: PREPARE hoge_200
AS SELECT * FROM pgbench_accounts WHERE aid =
1111111111111111111111111111111111111...
2021-03-17 15:21:01.942 JST [450855] LOG: level: 3 CachedPlanQuery:
4096 total in 3 blocks; 464 free (0 chunks); 3632 used
..(snip)..
2021-03-17 15:21:01.945 JST [450855] LOG: level: 1 Timezones: 104128
total in 2 blocks; 2584 free (0 chunks); 101544 used
2021-03-17 15:21:01.945 JST [450855] LOG: level: 1 ErrorContext: 8192
total in 1 blocks; 7928 free (5 chunks); 264 used
2021-03-17 15:21:01.945 JST [450855] LOG: Grand total: 2802080 bytes
in 1399 blocks; 480568 free (178 chunks); 2321512 used
As above, the output is almost the same as MemoryContextStatsPrint()
except for the way of expression of the level.
MemoryContextStatsPrint() uses indents, but
pg_print_backend_memory_contexts() writes it as "level: %d".
Since there was discussion about enlarging StringInfo may cause
errors on OOM[1], this patch calls elog for each context.
As with MemoryContextStatsPrint(), each context shows 100
children at most.
I once thought it should be configurable, but something like
pg_print_backend_memory_contexts(PID, num_children) needs to send
the 'num_children' from requestor to dumper and it seems to require
another infrastructure.
Creating a new GUC for this seems overkill.
If MemoryContextStatsPrint(), i.e. showing 100 children at most is
enough, this hard limit may be acceptable.
Only superusers can call pg_print_backend_memory_contexts().
I'm going to add documentation and regression tests.
Any thoughts?
[1]
https://www.postgresql.org/message-id/CAMsr%2BYGh%2Bsso5N6Q%2BFmYHLWC%3DBPCzA%2B5GbhYZSGruj2d0c7Vvg%...
"r_d/strengthen_perf/print_memcon.md" 110L, 5642C written
Regards,
--
Atsushi Torikoshi
NTT DATA CORPORATION
Attachments:
[text/x-diff] v1-0001-Add-memorycontext-elog-print.patch (20.7K, ../70ae4b79eb8b0dcf42161c80a00e3f22@oss.nttdata.com/2-v1-0001-Add-memorycontext-elog-print.patch)
download | inline diff:
diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c
index c6a8d4611e..e116f4a1be 100644
--- a/src/backend/storage/ipc/procsignal.c
+++ b/src/backend/storage/ipc/procsignal.c
@@ -30,6 +30,7 @@
#include "storage/shmem.h"
#include "storage/sinval.h"
#include "tcop/tcopprot.h"
+#include "utils/memutils.h"
/*
* The SIGUSR1 signal is multiplexed to support signaling multiple event
@@ -440,6 +441,20 @@ HandleProcSignalBarrierInterrupt(void)
/* latch will be set by procsignal_sigusr1_handler */
}
+/*
+ * HandleProcSignalPrintMemoryContext
+ *
+ * Handle receipt of an interrupt indicating print memory context.
+ * Signal handler portion of interrupt handling.
+ */
+static void
+HandleProcSignalPrintMemoryContext(void)
+{
+ InterruptPending = true;
+ PrintMemoryContextPending = true;
+ /* latch will be set by procsignal_sigusr1_handler */
+}
+
/*
* Perform global barrier related interrupt checking.
*
@@ -580,6 +595,25 @@ ProcessProcSignalBarrier(void)
ConditionVariableBroadcast(&MyProcSignalSlot->pss_barrierCV);
}
+/*
+ * ProcessPrintMemoryContextInterrupt
+ * The portion of print memory context interrupt handling that runs
+ * outside of the signal handler.
+ */
+void
+ProcessPrintMemoryContextInterrupt(void)
+{
+ PrintMemoryContextPending = false;
+
+ ereport(LOG,
+ (errmsg("Printing memory contexts of PID %d", MyProcPid)));
+
+ /* A hard-wired limit on the number of children is usually good enough */
+ MemoryContextStatsDetail(TopMemoryContext, 100, false);
+
+}
+
+
/*
* If it turns out that we couldn't absorb one or more barrier types, either
* because the barrier-processing functions returned false or due to an error,
@@ -675,6 +709,9 @@ procsignal_sigusr1_handler(SIGNAL_ARGS)
if (CheckProcSignal(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN))
RecoveryConflictInterrupt(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN);
+ if (CheckProcSignal(PROCSIG_PRINT_MEMORY_CONTEXT))
+ HandleProcSignalPrintMemoryContext();
+
SetLatch(MyLatch);
errno = save_errno;
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 2b1b68109f..6fe47d1229 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3295,6 +3295,9 @@ ProcessInterrupts(void)
if (ParallelMessagePending)
HandleParallelMessages();
+
+ if (PrintMemoryContextPending)
+ ProcessPrintMemoryContextInterrupt();
}
diff --git a/src/backend/utils/adt/mcxtfuncs.c b/src/backend/utils/adt/mcxtfuncs.c
index c02fa47550..07a95dd115 100644
--- a/src/backend/utils/adt/mcxtfuncs.c
+++ b/src/backend/utils/adt/mcxtfuncs.c
@@ -61,7 +61,7 @@ PutMemoryContextsStatsTupleStore(Tuplestorestate *tupstore,
/* Examine the context itself */
memset(&stat, 0, sizeof(stat));
- (*context->methods->stats) (context, NULL, (void *) &level, &stat);
+ (*context->methods->stats) (context, NULL, (void *) &level, &stat, true);
memset(values, 0, sizeof(values));
memset(nulls, 0, sizeof(nulls));
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 73e0a672ae..32fe971386 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -34,6 +34,7 @@ volatile sig_atomic_t ClientConnectionLost = false;
volatile sig_atomic_t IdleInTransactionSessionTimeoutPending = false;
volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
+volatile sig_atomic_t PrintMemoryContextPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c
index ec6c130d0f..8e7fe09a0f 100644
--- a/src/backend/utils/mmgr/aset.c
+++ b/src/backend/utils/mmgr/aset.c
@@ -272,7 +272,8 @@ static Size AllocSetGetChunkSpace(MemoryContext context, void *pointer);
static bool AllocSetIsEmpty(MemoryContext context);
static void AllocSetStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
static void AllocSetCheck(MemoryContext context);
@@ -1336,11 +1337,12 @@ AllocSetIsEmpty(MemoryContext context)
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
+ * is_dst_stderr: is the output should be stderr or elog.
*/
static void
AllocSetStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals, bool is_dst_stderr)
{
AllocSet set = (AllocSet) context;
Size nblocks = 0;
@@ -1379,7 +1381,7 @@ AllocSetStats(MemoryContext context,
"%zu total in %zd blocks; %zu free (%zd chunks); %zu used",
totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
- printfunc(context, passthru, stats_string);
+ printfunc(context, passthru, stats_string, is_dst_stderr);
}
if (totals)
diff --git a/src/backend/utils/mmgr/generation.c b/src/backend/utils/mmgr/generation.c
index 2b90034764..b286308aa4 100644
--- a/src/backend/utils/mmgr/generation.c
+++ b/src/backend/utils/mmgr/generation.c
@@ -155,7 +155,8 @@ static Size GenerationGetChunkSpace(MemoryContext context, void *pointer);
static bool GenerationIsEmpty(MemoryContext context);
static void GenerationStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
static void GenerationCheck(MemoryContext context);
@@ -665,6 +666,7 @@ GenerationIsEmpty(MemoryContext context)
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
+ * is_dst_stderr: is the output should be stderr or elog.
*
* XXX freespace only accounts for empty space at the end of the block, not
* space of freed chunks (which is unknown).
@@ -672,7 +674,7 @@ GenerationIsEmpty(MemoryContext context)
static void
GenerationStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals, bool is_dst_stderr)
{
GenerationContext *set = (GenerationContext *) context;
Size nblocks = 0;
@@ -704,7 +706,7 @@ GenerationStats(MemoryContext context,
"%zu total in %zd blocks (%zd chunks); %zu free (%zd chunks); %zu used",
totalspace, nblocks, nchunks, freespace,
nfreechunks, totalspace - freespace);
- printfunc(context, passthru, stats_string);
+ printfunc(context, passthru, stats_string, is_dst_stderr);
}
if (totals)
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index 84472b9158..9ec0c0509d 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -23,6 +23,10 @@
#include "mb/pg_wchar.h"
#include "miscadmin.h"
+#include "storage/proc.h"
+#include "storage/procarray.h"
+#include "storage/procsignal.h"
+#include "utils/fmgrprotos.h"
#include "utils/memdebug.h"
#include "utils/memutils.h"
@@ -55,9 +59,11 @@ MemoryContext PortalContext = NULL;
static void MemoryContextCallResetCallbacks(MemoryContext context);
static void MemoryContextStatsInternal(MemoryContext context, int level,
bool print, int max_children,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
static void MemoryContextStatsPrint(MemoryContext context, void *passthru,
- const char *stats_string);
+ const char *stats_string,
+ bool is_dst_stderr);
/*
* You should not do memory allocations within a critical section, because
@@ -487,6 +493,55 @@ MemoryContextMemAllocated(MemoryContext context, bool recurse)
return total;
}
+/*
+ * pg_print_backend_memory_contexts
+ * Print memory context of the specified backend process.
+ */
+Datum
+pg_print_backend_memory_contexts(PG_FUNCTION_ARGS)
+{
+ int pid = PG_GETARG_INT32(0);
+ PGPROC *proc = BackendPidGetProc(pid);
+
+ /*
+ * Check whether the target process is PostgreSQL backend process.
+ */
+ if (proc == NULL)
+ {
+ /*
+ * According to the thread below, it might be better to
+ * change this message.
+ *
+ * https://www.postgresql.org/message-id/CALj2ACW7Rr-R7mBcBQiXWPp%3DJV5chajjTdudLiF5YcpW-BmHhg%40mail.gmail.com
+ *
+ * Until the conclusion of the discussion, output the same
+ * message as pg_cancel_backend().
+ */
+ ereport(WARNING,
+ (errmsg("PID %d is not a PostgreSQL server process", pid)));
+
+ PG_RETURN_BOOL(false);
+ }
+
+ /* Only allow superusers to signal superuser-owned backends. */
+ if (superuser_arg(proc->roleId) && !superuser())
+ {
+ ereport(WARNING,
+ (errmsg("must be a superuser to print memory contexts")));
+ PG_RETURN_BOOL(false);
+ }
+
+ if(!SendProcSignal(pid, PROCSIG_PRINT_MEMORY_CONTEXT, InvalidBackendId))
+ PG_RETURN_BOOL(true);
+ else
+ {
+ ereport(WARNING,
+ (errmsg("failed to send signal: %m")));
+
+ PG_RETURN_BOOL(false);
+ }
+}
+
/*
* MemoryContextStats
* Print statistics about the named context and all its descendants.
@@ -499,7 +554,7 @@ void
MemoryContextStats(MemoryContext context)
{
/* A hard-wired limit on the number of children is usually good enough */
- MemoryContextStatsDetail(context, 100);
+ MemoryContextStatsDetail(context, 100, true);
}
/*
@@ -508,19 +563,28 @@ MemoryContextStats(MemoryContext context)
* Entry point for use if you want to vary the number of child contexts shown.
*/
void
-MemoryContextStatsDetail(MemoryContext context, int max_children)
+MemoryContextStatsDetail(MemoryContext context, int max_children, bool is_dst_stderr)
{
MemoryContextCounters grand_totals;
memset(&grand_totals, 0, sizeof(grand_totals));
- MemoryContextStatsInternal(context, 0, true, max_children, &grand_totals);
+ MemoryContextStatsInternal(context, 0, true, max_children, &grand_totals, is_dst_stderr);
- fprintf(stderr,
- "Grand total: %zu bytes in %zd blocks; %zu free (%zd chunks); %zu used\n",
- grand_totals.totalspace, grand_totals.nblocks,
- grand_totals.freespace, grand_totals.freechunks,
- grand_totals.totalspace - grand_totals.freespace);
+ if (is_dst_stderr)
+ fprintf(stderr,
+ "Grand total: %zu bytes in %zd blocks; %zu free (%zd chunks); %zu used\n",
+ grand_totals.totalspace, grand_totals.nblocks,
+ grand_totals.freespace, grand_totals.freechunks,
+ grand_totals.totalspace - grand_totals.freespace);
+ else
+ ereport(LOG_SERVER_ONLY,
+ (errhidestmt(true),
+ errhidecontext(true),
+ errmsg_internal("Grand total: %zu bytes in %zd blocks; %zu free (%zd chunks); %zu used",
+ grand_totals.totalspace, grand_totals.nblocks,
+ grand_totals.freespace, grand_totals.freechunks,
+ grand_totals.totalspace - grand_totals.freespace)));
}
/*
@@ -533,7 +597,8 @@ MemoryContextStatsDetail(MemoryContext context, int max_children)
static void
MemoryContextStatsInternal(MemoryContext context, int level,
bool print, int max_children,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals,
+ bool is_dst_stderr)
{
MemoryContextCounters local_totals;
MemoryContext child;
@@ -545,7 +610,7 @@ MemoryContextStatsInternal(MemoryContext context, int level,
context->methods->stats(context,
print ? MemoryContextStatsPrint : NULL,
(void *) &level,
- totals);
+ totals, is_dst_stderr);
/*
* Examine children. If there are more than max_children of them, we do
@@ -560,11 +625,13 @@ MemoryContextStatsInternal(MemoryContext context, int level,
if (ichild < max_children)
MemoryContextStatsInternal(child, level + 1,
print, max_children,
- totals);
+ totals,
+ is_dst_stderr);
else
MemoryContextStatsInternal(child, level + 1,
false, max_children,
- &local_totals);
+ &local_totals,
+ is_dst_stderr);
}
/* Deal with excess children */
@@ -574,16 +641,31 @@ MemoryContextStatsInternal(MemoryContext context, int level,
{
int i;
- for (i = 0; i <= level; i++)
- fprintf(stderr, " ");
- fprintf(stderr,
- "%d more child contexts containing %zu total in %zd blocks; %zu free (%zd chunks); %zu used\n",
- ichild - max_children,
- local_totals.totalspace,
- local_totals.nblocks,
- local_totals.freespace,
- local_totals.freechunks,
- local_totals.totalspace - local_totals.freespace);
+ if (is_dst_stderr)
+ {
+ for (i = 0; i <= level; i++)
+ fprintf(stderr, " ");
+ fprintf(stderr,
+ "%d more child contexts containing %zu total in %zd blocks; %zu free (%zd chunks); %zu used\n",
+ ichild - max_children,
+ local_totals.totalspace,
+ local_totals.nblocks,
+ local_totals.freespace,
+ local_totals.freechunks,
+ local_totals.totalspace - local_totals.freespace);
+ }
+ else
+ ereport(LOG_SERVER_ONLY,
+ (errhidestmt(true),
+ errhidecontext(true),
+ errmsg_internal("level: %d %d more child contexts containing %zu total in %zd blocks; %zu free (%zd chunks); %zu used",
+ level,
+ ichild - max_children,
+ local_totals.totalspace,
+ local_totals.nblocks,
+ local_totals.freespace,
+ local_totals.freechunks,
+ local_totals.totalspace - local_totals.freespace)));
}
if (totals)
@@ -605,12 +687,14 @@ MemoryContextStatsInternal(MemoryContext context, int level,
*/
static void
MemoryContextStatsPrint(MemoryContext context, void *passthru,
- const char *stats_string)
+ const char *stats_string,
+ bool is_dst_stderr)
{
int level = *(int *) passthru;
const char *name = context->name;
const char *ident = context->ident;
int i;
+ char truncated_ident[110];
/*
* It seems preferable to label dynahash contexts with just the hash table
@@ -623,11 +707,11 @@ MemoryContextStatsPrint(MemoryContext context, void *passthru,
ident = NULL;
}
- for (i = 0; i < level; i++)
- fprintf(stderr, " ");
- fprintf(stderr, "%s: %s", name, stats_string);
+ truncated_ident[0] = '\0';
+
if (ident)
{
+ char delimiter[] = ": ";
/*
* Some contexts may have very long identifiers (e.g., SQL queries).
* Arbitrarily truncate at 100 bytes, but be careful not to break
@@ -637,24 +721,42 @@ MemoryContextStatsPrint(MemoryContext context, void *passthru,
int idlen = strlen(ident);
bool truncated = false;
+ strcat(truncated_ident, delimiter);
+
if (idlen > 100)
{
idlen = pg_mbcliplen(ident, idlen, 100);
truncated = true;
}
- fprintf(stderr, ": ");
+
+ i = strlen(delimiter);
+
while (idlen-- > 0)
{
unsigned char c = *ident++;
if (c < ' ')
c = ' ';
- fputc(c, stderr);
+ truncated_ident[i++] = c;
}
+ truncated_ident[i] = '\0';
+
if (truncated)
- fprintf(stderr, "...");
+ strcat(truncated_ident, "...");
}
- fputc('\n', stderr);
+
+ if (is_dst_stderr)
+ {
+ for (i = 0; i < level; i++)
+ fprintf(stderr, " ");
+ fprintf(stderr, "%s: %s%s\n", name, stats_string, truncated_ident);
+ }
+ else
+ ereport(LOG_SERVER_ONLY,
+ (errhidestmt(true),
+ errhidecontext(true),
+ errmsg_internal("level: %d %s: %s%s",
+ level, name, stats_string, truncated_ident)));
}
/*
diff --git a/src/backend/utils/mmgr/slab.c b/src/backend/utils/mmgr/slab.c
index 9213be7c95..479b08bedd 100644
--- a/src/backend/utils/mmgr/slab.c
+++ b/src/backend/utils/mmgr/slab.c
@@ -135,7 +135,8 @@ static Size SlabGetChunkSpace(MemoryContext context, void *pointer);
static bool SlabIsEmpty(MemoryContext context);
static void SlabStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
static void SlabCheck(MemoryContext context);
#endif
@@ -632,11 +633,13 @@ SlabIsEmpty(MemoryContext context)
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
+ * is_dst_stderr: is the output should be stderr or elog.
*/
static void
SlabStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals,
+ bool is_dst_stderr)
{
SlabContext *slab = castNode(SlabContext, context);
Size nblocks = 0;
@@ -671,7 +674,7 @@ SlabStats(MemoryContext context,
"%zu total in %zd blocks; %zu free (%zd chunks); %zu used",
totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
- printfunc(context, passthru, stats_string);
+ printfunc(context, passthru, stats_string, is_dst_stderr);
}
if (totals)
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 93393fcfd4..0091806809 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7917,6 +7917,12 @@
proargnames => '{name, ident, parent, level, total_bytes, total_nblocks, free_bytes, free_chunks, used_bytes}',
prosrc => 'pg_get_backend_memory_contexts' },
+# print memory context of specified backend
+{ oid => '4543', descr => 'print memory contexts of specified backend',
+ proname => 'pg_print_backend_memory_contexts',
+ provolatile => 'v', prorettype => 'bool',
+ proargtypes => 'int4', prosrc => 'pg_print_backend_memory_contexts' },
+
# non-persistent series generator
{ oid => '1066', descr => 'non-persistent series generator',
proname => 'generate_series', prorows => '1000',
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 013850ac28..711d6c2089 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -84,6 +84,7 @@ extern PGDLLIMPORT volatile sig_atomic_t ProcDiePending;
extern PGDLLIMPORT volatile sig_atomic_t IdleInTransactionSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
+extern PGDLLIMPORT volatile sig_atomic_t PrintMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/nodes/memnodes.h b/src/include/nodes/memnodes.h
index 9331ef80fd..87a8501c37 100644
--- a/src/include/nodes/memnodes.h
+++ b/src/include/nodes/memnodes.h
@@ -52,7 +52,8 @@ typedef struct MemoryContextCounters
*/
typedef void (*MemoryStatsPrintFunc) (MemoryContext context, void *passthru,
- const char *stats_string);
+ const char *stats_string,
+ bool is_dst_stderr);
typedef struct MemoryContextMethods
{
@@ -66,7 +67,8 @@ typedef struct MemoryContextMethods
bool (*is_empty) (MemoryContext context);
void (*stats) (MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
void (*check) (MemoryContext context);
#endif
diff --git a/src/include/storage/procsignal.h b/src/include/storage/procsignal.h
index 4ae7dc33b8..0bfe290477 100644
--- a/src/include/storage/procsignal.h
+++ b/src/include/storage/procsignal.h
@@ -34,6 +34,8 @@ typedef enum
PROCSIG_PARALLEL_MESSAGE, /* message from cooperating parallel backend */
PROCSIG_WALSND_INIT_STOPPING, /* ask walsenders to prepare for shutdown */
PROCSIG_BARRIER, /* global barrier interrupt */
+ PROCSIG_PRINT_MEMORY_CONTEXT, /* ask specified backend to print the
+ memory context */
/* Recovery conflict reasons */
PROCSIG_RECOVERY_CONFLICT_DATABASE,
@@ -69,6 +71,7 @@ extern int SendProcSignal(pid_t pid, ProcSignalReason reason,
extern uint64 EmitProcSignalBarrier(ProcSignalBarrierType type);
extern void WaitForProcSignalBarrier(uint64 generation);
extern void ProcessProcSignalBarrier(void);
+extern void ProcessPrintMemoryContextInterrupt(void);
extern void procsignal_sigusr1_handler(SIGNAL_ARGS);
diff --git a/src/include/utils/memutils.h b/src/include/utils/memutils.h
index 36aae4e51c..fd10f80eda 100644
--- a/src/include/utils/memutils.h
+++ b/src/include/utils/memutils.h
@@ -84,7 +84,8 @@ extern MemoryContext MemoryContextGetParent(MemoryContext context);
extern bool MemoryContextIsEmpty(MemoryContext context);
extern Size MemoryContextMemAllocated(MemoryContext context, bool recurse);
extern void MemoryContextStats(MemoryContext context);
-extern void MemoryContextStatsDetail(MemoryContext context, int max_children);
+extern void MemoryContextStatsDetail(MemoryContext context, int max_children,
+ bool is_dst_stderr);
extern void MemoryContextAllowInCriticalSection(MemoryContext context,
bool allow);
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To: pgsql-hackers@postgresql.org
Cc: torikoshia@oss.nttdata.com, masao.fujii@oss.nttdata.com, tgl@sss.pgh.pa.us, gkokolatos@protonmail.com, kasahara.tatsuhito@gmail.com, craig@2ndquadrant.com
Subject: Re: Get memory contexts of an arbitrary backend process
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