Horton

Re: Keep elog(ERROR) and ereport(ERROR) calls in the cold path

David Rowley <dgrowleyml@gmail.com>

View thread View on postgr.es
From: David Rowley <dgrowleyml@gmail.com>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: Andres Freund <andres@anarazel.de>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2020-09-29T09:26:06Z
Lists: pgsql-hackers 
On Wed, 23 Sep 2020 at 08:42, David Rowley <dgrowleyml@gmail.com> wrote:
>
> On Tue, 22 Sep 2020 at 19:08, David Rowley <dgrowleyml@gmail.com> wrote:
> > I ran another scale=5 TPCH benchmark on v4 against f859c2ffa using gcc
> > 9.3. I'm unable to see any gains with this, however, the results were
> > pretty noisy. I only ran pgbench for 60 seconds per query. I'll likely
> > need to run that a bit longer. I'll do that tonight.
>
> I've attached the results of a TPCH scale=5 run master (f859c2ffa) vs
> master + elog_ereport_attribute_cold_v4.patch
>
> It does not look great. The patched version seems to have done about
> 1.17% less work than master did.

I've marked this patch back as waiting for review. It would be good if
someone could run some tests on some intel hardware and see if they
can see any speedup.

David

Commits

  1. Stop gap fix for __attribute__((cold)) compiler bug in MinGW 8.1

  2. Tidy up definitions of pg_attribute_hot and pg_attribute_cold

  3. Fix unportable usage of __has_attribute

  4. Improve compiler code layout in elog/ereport ERROR calls

  5. Define pg_attribute_cold and pg_attribute_hot macros