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base repository: postgresql-cfbot/postgresql
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base: cf/5919~1
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head repository: postgresql-cfbot/postgresql
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compare: cf/5919
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  • 4 commits
  • 3 files changed
  • 2 contributors

Commits on Oct 30, 2025

  1. Refactor goto into for loop in GetVictimBuffer() 

    GetVictimBuffer() implemented a loop to optimistically lock a clean
victim buffer using a goto. Future commits will add batch flushing
functionality to GetVictimBuffer. The new logic works better with
standard for loop flow control.

This commit is only a refactor and does not introduce any new
functionality.

Author: Melanie Plageman <[email protected]>
Reviewed-by: Nazir Bilal Yavuz <[email protected]>
Reviewed-by: Chao Li <[email protected]>
Discussion: https://postgr.es/m/2FA0BAC7-5413-4ABD-94CA-4398FE77750D%40gmail.com
Discussion: https://postgr.es/m/flat/CAAKRu_Yjn4mvN9NBxtmsCQSGwup45CoA4e05nhR7ADP-v0WCig%40mail.gmail.com
    @melanieplageman
    melanieplageman authored and Commitfest Bot committed Oct 30, 2025
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  2. Split FlushBuffer() into two parts 

    Before adding write combining to write a batch of blocks when flushing
dirty buffers, refactor FlushBuffer() into the preparatory step and
actual buffer flushing step. This separation procides symmetry with
future code for batch flushing which necessarily separates these steps,
as it must prepare multiple buffers before flushing them together.

These steps are moved into a new FlushBuffer() helper function,
CleanVictimBuffer() which will contain both the batch flushing and
single flush code in future commits.

Author: Melanie Plageman <[email protected]>
Reviewed-by: Chao Li <[email protected]>
Reviewed-by: Nazir Bilal Yavuz <[email protected]>
Discussion: https://postgr.es/m/2FA0BAC7-5413-4ABD-94CA-4398FE77750D%40gmail.com
Discussion: https://postgr.es/m/flat/CAAKRu_Yjn4mvN9NBxtmsCQSGwup45CoA4e05nhR7ADP-v0WCig%40mail.gmail.com
    @melanieplageman
    melanieplageman authored and Commitfest Bot committed Oct 30, 2025
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  3. Eagerly flush bulkwrite strategy ring 

    Operations using BAS_BULKWRITE (COPY FROM and createdb) will inevitably
need to flush buffers in the strategy ring in order to reuse them. By
eagerly flushing the buffers in a larger run, we encourage larger writes
at the kernel level and less interleaving of WAL flushes and data file
writes. The effect is mainly noticeable with multiple parallel COPY
FROMs. In this case, client backends achieve higher write throughput and
end up spending less time waiting on acquiring the lock to flush WAL.
Larger flush operations also mean less time waiting for flush operations
at the kernel level.

The heuristic for eager eviction is to only flush buffers in the
strategy ring which do not require a WAL flush.

This patch also is a step toward AIO writes.

Reviewed-by: Chao Li <[email protected]>
Reviewed-by: Nazir Bilal Yavuz <[email protected]>
Earlier version Reviewed-by: Kirill Reshke <[email protected]>
Discussion: https://postgr.es/m/2FA0BAC7-5413-4ABD-94CA-4398FE77750D%40gmail.com
Discussion: https://postgr.es/m/flat/CAAKRu_Yjn4mvN9NBxtmsCQSGwup45CoA4e05nhR7ADP-v0WCig%40mail.gmail.com
    @melanieplageman
    melanieplageman authored and Commitfest Bot committed Oct 30, 2025
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  4. [CF 5919] v5 - Eagerly evict bulkwrite strategy ring 

    This branch was automatically generated by a robot using patches from an
email thread registered at:

https://commitfest.postgresql.org/patch/5919

The branch will be overwritten each time a new patch version is posted to
the thread, and also periodically to check for bitrot caused by changes
on the master branch.

Patch(es): https://www.postgresql.org/message-id/CAAKRu_Y9WeWb5fu7Aibh-qGZuFYq3=57Y4ptSrzLYCnRWDHCow@mail.gmail.com
Author(s): Melanie Plageman
    Commitfest Bot committed Oct 30, 2025
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