Re: Checkpointer write combining

Melanie Plageman <melanieplageman@gmail.com>

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From: Melanie Plageman <melanieplageman@gmail.com>

To: Nazir Bilal Yavuz <byavuz81@gmail.com>

Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>

Date: 2025-09-09T13:39:19Z

Lists: pgsql-hackers

Attachments

v3-0003-Eagerly-flush-bulkwrite-strategy-ring.patch (text/x-patch) patch v3-0003
v3-0001-Refactor-goto-into-for-loop-in-GetVictimBuffer.patch (text/x-patch) patch v3-0001
v3-0002-Split-FlushBuffer-into-two-parts.patch (text/x-patch) patch v3-0002
v3-0005-Fix-XLogNeedsFlush-for-checkpointer.patch (text/x-patch) patch v3-0005
v3-0004-Write-combining-for-BAS_BULKWRITE.patch (text/x-patch) patch v3-0004
v3-0007-Implement-checkpointer-data-write-combining.patch (text/x-patch) patch v3-0007
v3-0006-Add-database-Oid-to-CkptSortItem.patch (text/x-patch) patch v3-0006

On Tue, Sep 9, 2025 at 9:27 AM Nazir Bilal Yavuz <byavuz81@gmail.com> wrote:
>

Thanks for the review!

> From 053dd9d15416d76ce4b95044d848f51ba13a2d20 Mon Sep 17 00:00:00 2001
> From: Melanie Plageman <melanieplageman@gmail.com>
> Date: Tue, 2 Sep 2025 11:00:44 -0400
> Subject: [PATCH v2 1/9] Refactor goto into for loop in GetVictimBuffer()
>
> @@ -731,6 +741,13 @@ StrategyRejectBuffer(BufferAccessStrategy
> strategy, BufferDesc *buf, bool from_r
>          strategy->buffers[strategy->current] != BufferDescriptorGetBuffer(buf))
>          return false;
>
> +    buf_state = LockBufHdr(buf);
> +    lsn = BufferGetLSN(buf);
> +    UnlockBufHdr(buf, buf_state);
> +
> +    if (!XLogNeedsFlush(lsn))
> +        return true;
>
> I think this should return false.

Oops, you're right. v3 attached with that mistake fixed.

- Melanie