Re: Performance degradation in commit ac1d794

2015-12-25 20:18 GMT+03:00 Andres Freund <andres(at)anarazel(dot)de>:

> On December 25, 2015 6:08:15 PM GMT+01:00, "Васильев Дмитрий" <
> d(dot)vasilyev(at)postgrespro(dot)ru> wrote:
> >Hello hackers!
> >
> >I suddenly found commit ac1d794 gives up to 3 times performance
> >degradation.
> >
> >I tried to run pgbench -s 1000 -j 48 -c 48 -S -M prepared on 70
> >CPU-core
> >machine:
> >commit ac1d794 gives me 363,474 tps
> >and previous commit a05dc4d gives me 956,146
> >and master( 3d0c50f ) with revert ac1d794 gives me 969,265
> >
> >it's shocking
>
>
>
> ​
> You're talking about
> http://git.postgresql.org/gitweb/?p=postgresql.git;a=blobdiff;f=src/backend/libpq/be-secure.c;h=2ddcf428f89fd12c230d6f417c2f707fbd97bf39;hp=26d8faaf773a818b388b899b8d83d617bdf7af9b;hb=ac1d794;hpb=a05dc4d7fd57d4ae084c1f0801973e5c1a1aa26e
>
> ​​
> If so, could you provide a hierarchical before/after profile?
>
> Andres
> Hi,
>
> ---
> Please excuse brevity and formatting - I am writing this on my mobile
> phone.
>

​> ​You're talking about
http://git.postgresql.org/gitweb/?p=postgresql.git;a=blobdiff;f=src/backend/libpq/be-secure.c;h=2ddcf428f89fd12c230d6f417c2f707fbd97bf39;hp=26d8faaf773a818b388b899b8d83d617bdf7af9b;hb=ac1d794;hpb=a05dc4d7fd57d4ae084c1f0801973e5c1a1aa26e

Yes, about this.

>​If so, could you provide a hierarchical before/after profile?

​Performance | Git hash commit | Date
~ 360k tps | c3e7c24a1d60dc6ad56e2a0723399f1570c54224 | Thu Nov 12 09:12:18
2015 -0500
~ 360k tps | ac1d7945f866b1928c2554c0f80fd52d7f977772 | Thu Nov 12
09:00:33 2015 -0500
~ 960k tps | a05dc4d7fd57d4ae084c1f0801973e5c1a1aa26e | Thu Nov 12
07:40:31 2015 -0500

​​---
Dmitry Vasilyev
Postgres Professional: http://www.postgrespro.com
Russian Postgres Company​