Horton

Re: WAL Insertion Lock Improvements

Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

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From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Nathan Bossart <nathandbossart@gmail.com>, Andres Freund <andres@anarazel.de>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-06-05T02:30:00Z
Lists: pgsql-hackers 
On Wed, May 31, 2023 at 5:05 PM Michael Paquier <michael@paquier.xyz> wrote:
>
> On Mon, May 22, 2023 at 09:26:25AM +0900, Michael Paquier wrote:
> > Simpler and consistent, nice.  I don't have much more to add, so I
> > have switched the patch as RfC.
>
> While at PGcon, Andres has asked me how many sockets are in the
> environment I used for the tests,

I'm glad to know that the feature was discussed at PGCon.

> and lscpu tells me the following,
> which is more than 1:
> CPU(s):                          64
> On-line CPU(s) list:             0-63
> Core(s) per socket:              16
> Socket(s):                       2
> NUMA node(s):                    2

Mine says this:

CPU(s):                  96
  On-line CPU(s) list:   0-95
Core(s) per socket:  24
Socket(s):           2
NUMA:
  NUMA node(s):          2
  NUMA node0 CPU(s):     0-23,48-71
  NUMA node1 CPU(s):     24-47,72-95

> @Andres: Were there any extra tests you wanted to be run for more
> input?

@Andres Freund please let us know your thoughts.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com

Commits

  1. Optimize pg_atomic_exchange_u32 and pg_atomic_exchange_u64.

  2. Document more assumptions of LWLock variable changes with WAL inserts

  3. Optimize WAL insertion lock acquisition and release with some atomics

  4. Avoid the use of a separate spinlock to protect a LWLock's wait queue.