Re: Enhancing Memory Context Statistics Reporting - Mailing list pgsql-hackers

From Daniel Gustafsson
Subject Re: Enhancing Memory Context Statistics Reporting
Date
Msg-id 43D5E807-AC37-4136-85FD-15B6F1BEF840@yesql.se
Whole thread Raw
In response to Re: Enhancing Memory Context Statistics Reporting  (Rahila Syed <rahilasyed90@gmail.com>)
List pgsql-hackers
> On 9 Jan 2026, at 12:22, Rahila Syed <rahilasyed90@gmail.com> wrote:

> After further discussion and reviewing Robert's email[1] on this topic, a safer solution
> is to avoid running ProcessGetMemoryContextInterrupt during an aborted transaction.
> This should help prevent additional errors when the transaction is already in error handling
> state.  Also, reporting memory context statistics from an aborting transaction won't
> be very useful as some of that memory usage won't be valid after abort completes.

+1, I think was the right call to make.

> Attached is the updated patch that addresses this.

A few small comments on v47:

+static const char *ContextTypeToString(NodeTag type);
I think context_type_to_string() would be a better name on this internal
function to model it closer to the existing int_list_to_array().  Personally I
would also place it before its first use to avoid the prototype, but that's
personal preference.


+static void
+memstats_dsa_cleanup(char *key)
This function warrants a documentation comment describing when it should be
used safely.


+           memstats_dsa_cleanup(key);
+           memstats_client_key_reset(procNumber);
+           ConditionVariableCancelSleep();
+           PG_RETURN_NULL();
I think we should notify the user in these two timeout cases, why not adding an
ereport(NOTICE, "request for memory context statistics timed out")); or
something with a better wording than that.


+   Size        sz = 0;
+   Size        TotalProcs = 0;
+
+   TotalProcs = add_size(TotalProcs, NUM_AUXILIARY_PROCS);
+   TotalProcs = add_size(TotalProcs, MaxBackends);
+   sz = add_size(sz, mul_size(TotalProcs, sizeof(int)));
+
+   return sz
As we discussed off-list, the call to add_size() call can be omitted as it
won't affect the calculation.


+# Copyright (c) 2025, PostgreSQL Global Development Group
Here, and possibly elsewhere, it should say 2026 instead I think.

--
Daniel Gustafsson




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