Horton

Re: elog(DEBUG2 in SpinLocked section.

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, Amit Kapila <amit.kapila16@gmail.com>, pasim@vmware.com, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2020-06-09T23:24:15Z
Lists: pgsql-hackers 
Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Jun 9, 2020 at 1:59 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> When I went through the existing spinlock stanzas, the only thing that
>> really made me acutely uncomfortable was the chunk in pg_stat_statement's
>> pgss_store(), lines 1386..1438 in HEAD.

> I mean, what would be wrong with having an LWLock per pgss entry?

Hmm, maybe nothing.  I'm accustomed to thinking of them as being
significantly more expensive than spinlocks, but maybe we've narrowed
the gap enough that that's not such a problem.

			regards, tom lane

Commits

  1. Fix instance of elog() called while holding a spinlock

  2. Don't call palloc() while holding a spinlock, either.

  3. Don't call elog() while holding spinlock.