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pgsql: aio: Combine io_uring memory mappings, if supported 2+ messages / 1 participants [nested] [flat]
* pgsql: aio: Combine io_uring memory mappings, if supported @ 2025-07-08 03:20 Andres Freund <andres@anarazel.de> 0 siblings, 0 replies; 2+ messages in thread From: Andres Freund @ 2025-07-08 03:20 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org aio: Combine io_uring memory mappings, if supported By default io_uring creates a shared memory mapping for each io_uring instance, leading to a large number of memory mappings. Unfortunately a large number of memory mappings slows things down, backend exit is particularly affected. To address that, newer kernels (6.5) support using user-provided memory for the memory. By putting the relevant memory into shared memory we don't need any additional mappings. On a system with a new enough kernel and liburing, there is no discernible overhead when doing a pgbench -S -C anymore. Reported-by: MARK CALLAGHAN <mdcallag@gmail.com> Reviewed-by: "Burd, Greg" <greg@burd.me> Reviewed-by: Jim Nasby <jnasby@upgrade.com> Discussion: https://postgr.es/m/CAFbpF8OA44_UG+RYJcWH9WjF7E3GA6gka3gvH6nsrSnEe9H0NA@mail.gmail.com Backpatch-through: 18 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/f54af9f2679d5987b4680e742ac9bd585260e620 Modified Files -------------- configure | 17 +++ configure.ac | 7 + meson.build | 6 + src/backend/storage/aio/method_io_uring.c | 210 +++++++++++++++++++++++++++++- src/include/pg_config.h.in | 3 + src/tools/pgindent/typedefs.list | 1 + 6 files changed, 238 insertions(+), 6 deletions(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
* pgsql: aio: Combine io_uring memory mappings, if supported @ 2025-07-08 03:20 Andres Freund <andres@anarazel.de> 0 siblings, 0 replies; 2+ messages in thread From: Andres Freund @ 2025-07-08 03:20 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org aio: Combine io_uring memory mappings, if supported By default io_uring creates a shared memory mapping for each io_uring instance, leading to a large number of memory mappings. Unfortunately a large number of memory mappings slows things down, backend exit is particularly affected. To address that, newer kernels (6.5) support using user-provided memory for the memory. By putting the relevant memory into shared memory we don't need any additional mappings. On a system with a new enough kernel and liburing, there is no discernible overhead when doing a pgbench -S -C anymore. Reported-by: MARK CALLAGHAN <mdcallag@gmail.com> Reviewed-by: "Burd, Greg" <greg@burd.me> Reviewed-by: Jim Nasby <jnasby@upgrade.com> Discussion: https://postgr.es/m/CAFbpF8OA44_UG+RYJcWH9WjF7E3GA6gka3gvH6nsrSnEe9H0NA@mail.gmail.com Backpatch-through: 18 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/9a5334c0b4e9d7269ee9b5e9d08925c8a1e1e01e Modified Files -------------- configure | 17 +++ configure.ac | 7 + meson.build | 6 + src/backend/storage/aio/method_io_uring.c | 210 +++++++++++++++++++++++++++++- src/include/pg_config.h.in | 3 + src/tools/pgindent/typedefs.list | 1 + 6 files changed, 238 insertions(+), 6 deletions(-) ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2025-07-08 03:20 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2025-07-08 03:20 pgsql: aio: Combine io_uring memory mappings, if supported Andres Freund <andres@anarazel.de> 2025-07-08 03:20 pgsql: aio: Combine io_uring memory mappings, if supported Andres Freund <andres@anarazel.de>
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