hcq/postgresql
1
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2026-02-21 13:56:59 +08:00
Code Issues Packages Projects Releases Wiki Activity

aio: Combine io_uring memory mappings, if supported

Browse Source 
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
This commit is contained in:
Andres Freund
2025-07-07 21:03:16 -04:00
parent 3a797c2491
commit 9a5334c0b4
6 changed files with 238 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
src/include/pg_config.h.in
View File

@ -229,6 +229,9 @@
/* Define to 1 if you have the global variable 'int timezone'. */
#undef HAVE_INT_TIMEZONE
/* Define to 1 if you have the `io_uring_queue_init_mem' function. */
#undef HAVE_IO_URING_QUEUE_INIT_MEM
/* Define to 1 if __builtin_constant_p(x) implies "i"(x) acceptance. */
#undef HAVE_I_CONSTRAINT__BUILTIN_CONSTANT_P