From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: Daniel Gustafsson <dgustafsson@postgresql.org>,
        Andres Freund <andres@anarazel.de>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
        Rahila Syed <rahilasyed90@gmail.com>
Subject: Re: pgsql: Add function to get memory context stats for processes
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Wed, 23 Apr 2025 12:12:11 -0400"
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Date: Wed, 23 Apr 2025 14:14:34 -0400
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Robert Haas <robertmhaas@gmail.com> writes:
> My primary concern about the patch is that
> ProcessGetMemoryContextInterrupt() can be called from any
> CHECK_FOR_INTERRUPTS() and calls lots of DSA functions, including
> dsa_create() and, via PublishMemoryContext(), dsa_allocate0(). I'm
> shocked to hear that you and Andres think that's safe to do at any
> current or future CHECK_FOR_INTERRUPTS() anywhere in the code; but
> Andres seems very confident that it's fine, so perhaps I should just
> stop worrying and be happy that we have the feature.

Just for the record, it sounds quite unsafe to me too.  I could
credit it being all right to examine the process' MemoryContext data
structures, but calling dsa_create() from CFI seems really insane.
Way too many moving parts there.

			regards, tom lane