Re: Performance degradation in commit ac1d794 - Mailing list pgsql-hackers

2015-12-25 20:18 GMT+03:00 Andres Freund <andres@anarazel.de>:

On December 25, 2015 6:08:15 PM GMT+01:00, "Васильев Дмитрий" <d.vasilyev@postgrespro.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​