Horton

Re: heavily contended lwlocks with long wait queues scale badly

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Jakub Wartak <jakub.wartak@enterprisedb.com>
Cc: "Jonathan S. Katz" <jkatz@postgresql.org>, Nathan Bossart <nathandbossart@gmail.com>, Andres Freund <andres@anarazel.de>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, pgsql-hackers@postgresql.org, Thomas Munro <thomas.munro@gmail.com>, Yura Sokolov <y.sokolov@postgrespro.ru>
Date: 2024-01-22T08:38:13Z
Lists: pgsql-hackers 
On Fri, Jan 19, 2024 at 01:49:59PM +0100, Jakub Wartak wrote:
> Hi Michael, just to reassure you that it is a good thing. We have a
> customer who reported much better performance on 16.x than on 13~15 in
> very heavy duty LWLock/lockmanager scenarios (ofc, before that was
> committed/released), so I gave it a try here today to see how much can
> be attributed to that single commit.

Ahh.  Thanks for the feedback.
--
Michael

Commits

  1. lwlock: Fix quadratic behavior with very long wait lists