Horton

Re: MultiXact\SLRU buffers configuration

Daniel Gustafsson <daniel@yesql.se>

View thread View on postgr.es
From: Daniel Gustafsson <daniel@yesql.se>
To: "Andrey M. Borodin" <x4mmm@yandex-team.ru>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-08-02T21:30:21Z
Lists: pgsql-hackers 

> On 8 Jul 2020, at 09:03, Andrey M. Borodin <x4mmm@yandex-team.ru> wrote:
> 
> 
> 
>> 2 июля 2020 г., в 17:02, Daniel Gustafsson <daniel@yesql.se> написал(а):
>> 
>>> On 15 May 2020, at 02:03, Kyotaro Horiguchi <horikyota.ntt@gmail.com> wrote:
>> 
>>> Generally in such cases, condition variables would work.  In the
>>> attached PoC, the reader side gets no penalty in the "likely" code
>>> path.  The writer side always calls ConditionVariableBroadcast but the
>>> waiter list is empty in almost all cases.  But I couldn't cause the
>>> situation where the sleep 1000u is reached.
>> 
>> The submitted patch no longer applies, can you please submit an updated
>> version?  I'm marking the patch Waiting on Author in the meantime.
> Thanks, Daniel! PFA V2

This version too has stopped applying according to the CFbot.  I've moved it to
the next commitfest as we're out of time in this one and it was only pointed
out now, but kept it Waiting on Author.

cheers ./daniel

Commits

  1. Rework new SLRU test with injection points

  2. injection_point: Add injection_points.stats

  3. injection_points: Add initialization of shmem state when loading module

  4. Add injection-point test for new multixact CV usage

  5. Use conditional variable to wait for next MultiXact offset

  6. Improve performance of subsystems on top of SLRU

  7. Adjust VACUUM hastup LP_REDIRECT comments.

  8. Test replay of regression tests, attempt II.