From 55b454d0e14084c841a034073abbf1a0ea937a45 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Tue, 18 Mar 2025 10:52:33 -0400 Subject: aio: Infrastructure for io_method=worker This commit contains the basic, system-wide, infrastructure for io_method=worker. It does not yet actually execute IO, this commit just provides the infrastructure for running IO workers, kept separate for easier review. The number of IO workers can be adjusted with a PGC_SIGHUP GUC. Eventually we'd like to make the number of workers dynamically scale up/down based on the current "IO load". To allow the number of IO workers to be increased without a restart, we need to reserve PGPROC entries for the workers unconditionally. This has been judged to be worth the cost. If it turns out to be problematic, we can introduce a PGC_POSTMASTER GUC to control the maximum number. As io workers might be needed during shutdown, e.g. for AIO during the shutdown checkpoint, a new PMState phase is added. IO workers are shut down after the shutdown checkpoint has been performed and walsender/archiver have shut down, but before the checkpointer itself shuts down. See also 87a6690cc69. Updates PGSTAT_FILE_FORMAT_ID due to the addition of a new BackendType. Reviewed-by: Noah Misch Co-authored-by: Thomas Munro Co-authored-by: Andres Freund Discussion: https://postgr.es/m/uvrtrknj4kdytuboidbhwclo4gxhswwcpgadptsjvjqcluzmah%40brqs62irg4dt Discussion: https://postgr.es/m/20210223100344.llw5an2aklengrmn@alap3.anarazel.de Discussion: https://postgr.es/m/stj36ea6yyhoxtqkhpieia2z4krnam7qyetc57rfezgk4zgapf@gcnactj4z56m --- src/backend/utils/misc/postgresql.conf.sample | 1 + 1 file changed, 1 insertion(+) (limited to 'src/backend/utils/misc/postgresql.conf.sample') diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index db44fa563b5..7d0bf1dc006 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -207,6 +207,7 @@ # can execute simultaneously # -1 sets based on shared_buffers # (change requires restart) +#io_workers = 3 # 1-32; # - Worker Processes - -- cgit v1.2.3