Re: memory leak in auto_explain - Mailing list pgsql-hackers

From japin
Subject Re: memory leak in auto_explain
Date
Msg-id MEYP282MB1669B5A06AD6E45A7220B1F3B6B49@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
Whole thread Raw
In response to Re: memory leak in auto_explain  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Wed, 03 Feb 2021 at 02:13, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> japin <japinli@hotmail.com> writes:
>> Here's my analysis:
>> 1) In the explain_ExecutorEnd(), it will create a ExplainState on SQL function
>> memory context, which is a long-lived, cause the memory grow up.
>
> Yeah, agreed.  I think people looking at this have assumed that the
> ExecutorEnd hook would automatically be running in the executor's
> per-query context, but that's not so; we haven't yet entered
> standard_ExecutorEnd where the context switch is.  The caller's
> context is likely to be much longer-lived than the executor's.
>
> I think we should put the switch one level further out than you have
> it here, just to be sure that InstrEndLoop is covered too (that doesn't
> allocate memory, but auto_explain shouldn't assume that).  Otherwise
> seems like a good fix.
>

Thanks for your review and clarification.

-- 
Regrads,
Japin Li.
ChengDu WenWu Information Technology Co.,Ltd.



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