From 8f91d87d43d021db92c6edd966a4bb8c3a81ae39 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Sun, 24 Apr 2016 12:26:55 -0700 Subject: [PATCH] Fix documentation & config inconsistencies around 428b1d6b2. Several issues: 1) checkpoint_flush_after doc and code disagreed about the default 2) new GUCs were missing from postgresql.conf.sample 3) Outdated source-code comment about bgwriter_flush_after's default 4) Sub-optimal categories assigned to new GUCs 5) Docs suggested backend_flush_after is PGC_SIGHUP, but it's PGC_USERSET. 6) Spell out int as integer in the docs, as done elsewhere Reported-By: Magnus Hagander, Fujii Masao Discussion: CAHGQGwETyTG5VYQQ5C_srwxWX7RXvFcD3dKROhvAWWhoSBdmZw@mail.gmail.com --- doc/src/sgml/config.sgml | 10 ++-- src/backend/utils/misc/guc.c | 50 +++++++++---------- src/backend/utils/misc/postgresql.conf.sample | 6 +++ 3 files changed, 35 insertions(+), 31 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index f9ba148782..909b3e23c5 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1884,7 +1884,7 @@ include_dir 'conf.d' - bgwriter_flush_after (int) + bgwriter_flush_after (integer) bgwriter_flush_after configuration parameter @@ -2014,7 +2014,7 @@ include_dir 'conf.d' - backend_flush_after (int) + backend_flush_after (integer) backend_flush_after configuration parameter @@ -2036,8 +2036,6 @@ include_dir 'conf.d' and 2MB. The default is 128Kb on Linux, 0 elsewhere. (Non-default values of BLCKSZ change the default and maximum.) - This parameter can only be set in the postgresql.conf - file or on the server command line. @@ -2607,7 +2605,7 @@ include_dir 'conf.d' - checkpoint_flush_after (int) + checkpoint_flush_after (integer) checkpoint_flush_after configuration parameter @@ -2626,7 +2624,7 @@ include_dir 'conf.d' than the OS's page cache, where performance might degrade. This setting may have no effect on some platforms. The valid range is between 0, which disables controlled writeback, - and 2MB. The default is 128Kb on + and 2MB. The default is 256Kb on Linux, 0 elsewhere. (Non-default values of BLCKSZ change the default and maximum.) This parameter can only be set in the postgresql.conf diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index fb091bc4a0..60856dda19 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -2273,6 +2273,18 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"checkpoint_flush_after", PGC_SIGHUP, WAL_CHECKPOINTS, + gettext_noop("Number of pages after which previously performed writes are flushed to disk."), + NULL, + GUC_UNIT_BLOCKS + }, + &checkpoint_flush_after, + /* see bufmgr.h: OS dependent default */ + DEFAULT_CHECKPOINT_FLUSH_AFTER, 0, WRITEBACK_MAX_PENDING_FLUSHES, + NULL, NULL, NULL + }, + { {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS, gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."), @@ -2419,6 +2431,18 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"bgwriter_flush_after", PGC_SIGHUP, RESOURCES_BGWRITER, + gettext_noop("Number of pages after which previously performed writes are flushed to disk."), + NULL, + GUC_UNIT_BLOCKS + }, + &bgwriter_flush_after, + /* see bufmgr.h: OS dependent default */ + DEFAULT_BGWRITER_FLUSH_AFTER, 0, WRITEBACK_MAX_PENDING_FLUSHES, + NULL, NULL, NULL + }, + { {"effective_io_concurrency", PGC_USERSET, @@ -2436,19 +2460,7 @@ static struct config_int ConfigureNamesInt[] = }, { - {"checkpoint_flush_after", PGC_SIGHUP, RESOURCES_ASYNCHRONOUS, - gettext_noop("Number of pages after which previously performed writes are flushed to disk."), - NULL, - GUC_UNIT_BLOCKS - }, - &checkpoint_flush_after, - /* see bufmgr.h: OS dependent default */ - DEFAULT_CHECKPOINT_FLUSH_AFTER, 0, WRITEBACK_MAX_PENDING_FLUSHES, - NULL, NULL, NULL - }, - - { - {"backend_flush_after", PGC_USERSET, WAL_CHECKPOINTS, + {"backend_flush_after", PGC_USERSET, RESOURCES_ASYNCHRONOUS, gettext_noop("Number of pages after which previously performed writes are flushed to disk."), NULL, GUC_UNIT_BLOCKS @@ -2459,18 +2471,6 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, - { - {"bgwriter_flush_after", PGC_SIGHUP, WAL_CHECKPOINTS, - gettext_noop("Number of pages after which previously performed writes are flushed to disk."), - NULL, - GUC_UNIT_BLOCKS - }, - &bgwriter_flush_after, - /* see bufmgr.h: 16 on Linux, 0 otherwise */ - DEFAULT_BGWRITER_FLUSH_AFTER, 0, WRITEBACK_MAX_PENDING_FLUSHES, - NULL, NULL, NULL - }, - { {"max_worker_processes", PGC_POSTMASTER, diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index d4dd285ef0..14b537ffb1 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -160,6 +160,8 @@ #bgwriter_delay = 200ms # 10-10000ms between rounds #bgwriter_lru_maxpages = 100 # 0-1000 max buffers written/round #bgwriter_lru_multiplier = 2.0 # 0-10.0 multiplier on buffers scanned/round +#bgwriter_flush_after = 0 # 0 disables, + # default is 512kb on linux, 0 otherwise # - Asynchronous Behavior - @@ -168,6 +170,8 @@ #max_parallel_degree = 0 # max number of worker processes per node #old_snapshot_threshold = -1 # 1min-60d; -1 disables; 0 is immediate # (change requires restart) +#backend_flush_after = 0 # 0 disables, + # default is 128kb on linux, 0 otherwise #------------------------------------------------------------------------------ @@ -206,6 +210,8 @@ #max_wal_size = 1GB #min_wal_size = 80MB #checkpoint_completion_target = 0.5 # checkpoint target duration, 0.0 - 1.0 +#checkpoint_flush_after = 0 # 0 disables, + # default is 256kb on linux, 0 otherwise #checkpoint_warning = 30s # 0 disables # - Archiving -