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help / color / mirror / Atom feedFrom: Nathan Bossart <nathan@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Convert Sharedsort's worker counters to atomic variables.
Date: Tue, 22 Sep 2026 18:51:19 +0000
Message-ID: <E1x95aJ-00000000oE4-2Oyy@gemulon.postgresql.org> (raw)
Convert Sharedsort's worker counters to atomic variables.
Currently, currentWorker and workersFinished are ints protected by
a spinlock. By converting them to atomic variables, we can remove
the spinlock. Note that the spinlock also covered the write of
each worker's tape metadata. Removing it is still okay: each
worker writes only its own slot, and the atomic increment that
follows is a full barrier. Furthermore, the leader doesn't read
the slot values until all workers have finished.
Reviewed-by: Zsolt Parragi <zsolt.parragi@percona.com>
Tested-by: solai v <solai.cdac@gmail.com>
Discussion: https://postgr.es/m/alAJeRRzehDjLaF1%40nathan
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/ee97eef695e8be9153595131f8b63e4b1b3e8196
Modified Files
--------------
src/backend/utils/sort/tuplesort.c | 30 ++++++++----------------------
1 file changed, 8 insertions(+), 22 deletions(-)
Message-ID: <E1x95aJ-00000000oE4-2Oyy@gemulon.postgresql.org>
Permalink: ../E1x95aJ-00000000oE4-2Oyy@gemulon.postgresql.org/
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To: pgsql-committers@postgresql.org
Cc: nathan@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Convert Sharedsort's worker counters to atomic variables.
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