Re：Detach shared memory in Postmaster child if not needed

From: "Rui Zhao" <xiyuan(dot)zr(at)alibaba-inc(dot)com>
To: "Aleksander Alekseev" <aleksander(at)timescale(dot)com>, "pgsql-hackers" <pgsql-hackers(at)postgresql(dot)org>
Cc: "hlinnaka" <hlinnaka(at)iki(dot)fi>, "robertmhaas" <robertmhaas(at)gmail(dot)com>, "tgl" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Subject: Re：Detach shared memory in Postmaster child if not needed
Date: 2024-07-29 17:25:02
Message-ID: 45c4aac4-d94a-4bdb-a6f3-3655d8351915.xiyuan.zr@alibaba-inc.com
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Thanks for your reply.
> Thanks for the patch. How do you estimate its performance impact?
In my patch, ony child processes that set
(child_process_kinds[child_type].shmem_attach == false)
will detach from shared memory.
Child processes with B_STANDALONE_BACKEND and B_INVALID don't call
postmaster_child_launch().
Therefore, currently, only the syslogger will be affected,
which should be harmless.
> Note the comments for postmaster_child_launch(). This function is
> exposed to the third-party code and guarantees to attach shared
> memory. I doubt that there is much third-party code in existence to
> break but you should change to comment.
Thank you for your reminder. My v2 patch will include the comments for
postmaster_child_launch().
--
Best regards,
Rui Zhao

Attachment Content-Type Size
0001-Detach-shared-memory-in-Postmaster-child-if-not-needed-v2.patch application/octet-stream 1.5 KB

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