Horton

Re: pgsql: Add function to log the memory contexts of specified backend pro

torikoshia <torikoshia@oss.nttdata.com>

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From: torikoshia <torikoshia@oss.nttdata.com>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-05-02T05:58:29Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add guard to prevent recursive memory context logging.

  2. Add function to log the memory contexts of specified backend process.

  3. Add pg_backend_memory_contexts system view.

On 2025-05-02 09:02, Fujii Masao wrote:
> On 2025/05/02 2:27, Fujii Masao wrote:
>> 
>> 
>> On 2025/05/01 21:42, Robert Haas wrote:
>>> On Thu, May 1, 2025 at 3:53 AM Fujii Masao 
>>> <masao.fujii@oss.nttdata.com> wrote:
>>>> Just idea, what do you think about adding a flag to indicate whether
>>>> ProcessLogMemoryContextInterrupt() is currently running? Then,
>>>> when a backend receives a signal and 
>>>> ProcessLogMemoryContextInterrupt()
>>>> is invoked, it can simply return immediately if the flag is already 
>>>> set
>>>> like this:
>>> 
>>> I think that something like this could work, but you would need more
>>> than this. Otherwise, if the function errors out, the flag would
>>> remain permanently set.
>> 
>> Yes, we need to either use PG_TRY()/PG_FINALLY() or handle the flag as
>> a global variable and reset it in the error handling path. I think 
>> using
>> PG_TRY()/PG_FINALLY() is the simpler option.
> 
> I've implemented the patch in that way. Patch attached.

Thank you for the patch!

I confirmed that with this patch applied, the process no longer crashes 
even after applying the change Robert used to trigger the crash.

a small nitpick:

+                * requested  repeatedly and rapidly, potentially 
leading to infinite

It looks like there are two spaces between "requested" and "repeatedly".


-- 
Regards,

--
Atsushi Torikoshi
Seconded from NTT DATA GROUP CORPORATION to SRA OSS K.K.