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 --- doc/src/sgml/config.sgml | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'doc/src') diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 42e96b96f21..c749bc0631a 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -2689,6 +2689,25 @@ include_dir 'conf.d' + + io_workers (int) + + io_workers configuration parameter + + + + + Selects the number of I/O worker processes to use. The default is + 3. This parameter can only be set in the + postgresql.conf file or on the server command + line. + + + Only has an effect if is set to + worker. + + + -- cgit v1.2.3