From bcbd940806a2011d6f99ae72ea5897e8a94c6093 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Tue, 10 Jul 2018 17:37:42 +0200 Subject: [PATCH] Remove dynamic_shared_memory_type=none PostgreSQL nowadays offers some kind of dynamic shared memory feature on all supported platforms. Having the choice of "none" prevents us from relying on DSM in core features. So this patch removes the choice of "none". Author: Kyotaro Horiguchi --- doc/src/sgml/config.sgml | 6 +++--- doc/src/sgml/parallel.sgml | 8 -------- src/backend/access/transam/parallel.c | 7 ------- src/backend/optimizer/plan/planner.c | 4 +--- src/backend/storage/ipc/dsm.c | 15 -------------- src/backend/storage/ipc/dsm_impl.c | 3 --- src/backend/utils/misc/postgresql.conf.sample | 1 - src/bin/initdb/initdb.c | 20 ++++++++++++------- src/include/storage/dsm_impl.h | 1 - 9 files changed, 17 insertions(+), 48 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 5b913f00c1..e307bb4e8e 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1662,9 +1662,9 @@ include_dir 'conf.d' should use. Possible values are posix (for POSIX shared memory allocated using shm_open), sysv (for System V shared memory allocated via shmget), - windows (for Windows shared memory), mmap - (to simulate shared memory using memory-mapped files stored in the - data directory), and none (to disable this feature). + windows (for Windows shared memory), + and mmap (to simulate shared memory using + memory-mapped files stored in the data directory). Not all values are supported on all platforms; the first supported option is the default for that platform. The use of the mmap option, which is not the default on any platform, diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml index dd7834a763..e9a015ecd3 100644 --- a/doc/src/sgml/parallel.sgml +++ b/doc/src/sgml/parallel.sgml @@ -124,14 +124,6 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%'; configured via max_parallel_workers_per_gather. - - - - must be set to a - value other than none. Parallel query requires dynamic - shared memory in order to pass data between cooperating processes. - - diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c index 1d631b7275..4e32cfff50 100644 --- a/src/backend/access/transam/parallel.c +++ b/src/backend/access/transam/parallel.c @@ -161,13 +161,6 @@ CreateParallelContext(const char *library_name, const char *function_name, /* Number of workers should be non-negative. */ Assert(nworkers >= 0); - /* - * If dynamic shared memory is not available, we won't be able to use - * background workers. - */ - if (dynamic_shared_memory_type == DSM_IMPL_NONE) - nworkers = 0; - /* * If we are running under serializable isolation, we can't use parallel * workers, at least not until somebody enhances that mechanism to be diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index fd45c9767d..eeebf775a4 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -335,7 +335,6 @@ standard_planner(Query *parse, int cursorOptions, ParamListInfo boundParams) */ if ((cursorOptions & CURSOR_OPT_PARALLEL_OK) != 0 && IsUnderPostmaster && - dynamic_shared_memory_type != DSM_IMPL_NONE && parse->commandType == CMD_SELECT && !parse->hasModifyingCTE && max_parallel_workers_per_gather > 0 && @@ -6050,8 +6049,7 @@ plan_create_index_workers(Oid tableOid, Oid indexOid) double allvisfrac; /* Return immediately when parallelism disabled */ - if (dynamic_shared_memory_type == DSM_IMPL_NONE || - max_parallel_maintenance_workers == 0) + if (max_parallel_maintenance_workers == 0) return 0; /* Set up largely-dummy planner state */ diff --git a/src/backend/storage/ipc/dsm.c b/src/backend/storage/ipc/dsm.c index f1f75b73f5..9629f22f7a 100644 --- a/src/backend/storage/ipc/dsm.c +++ b/src/backend/storage/ipc/dsm.c @@ -150,10 +150,6 @@ dsm_postmaster_startup(PGShmemHeader *shim) Assert(!IsUnderPostmaster); - /* If dynamic shared memory is disabled, there's nothing to do. */ - if (dynamic_shared_memory_type == DSM_IMPL_NONE) - return; - /* * If we're using the mmap implementations, clean up any leftovers. * Cleanup isn't needed on Windows, and happens earlier in startup for @@ -219,10 +215,6 @@ dsm_cleanup_using_control_segment(dsm_handle old_control_handle) uint32 i; dsm_control_header *old_control; - /* If dynamic shared memory is disabled, there's nothing to do. */ - if (dynamic_shared_memory_type == DSM_IMPL_NONE) - return; - /* * Try to attach the segment. If this fails, it probably just means that * the operating system has been rebooted and the segment no longer @@ -391,13 +383,6 @@ dsm_postmaster_shutdown(int code, Datum arg) static void dsm_backend_startup(void) { - /* If dynamic shared memory is disabled, reject this. */ - if (dynamic_shared_memory_type == DSM_IMPL_NONE) - ereport(ERROR, - (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), - errmsg("dynamic shared memory is disabled"), - errhint("Set dynamic_shared_memory_type to a value other than \"none\"."))); - #ifdef EXEC_BACKEND { void *control_address = NULL; diff --git a/src/backend/storage/ipc/dsm_impl.c b/src/backend/storage/ipc/dsm_impl.c index c6382ec031..77e1bab54b 100644 --- a/src/backend/storage/ipc/dsm_impl.c +++ b/src/backend/storage/ipc/dsm_impl.c @@ -106,7 +106,6 @@ const struct config_enum_entry dynamic_shared_memory_options[] = { #ifdef USE_DSM_MMAP {"mmap", DSM_IMPL_MMAP, false}, #endif - {"none", DSM_IMPL_NONE, false}, {NULL, 0, false} }; @@ -210,8 +209,6 @@ dsm_impl_can_resize(void) { switch (dynamic_shared_memory_type) { - case DSM_IMPL_NONE: - return false; case DSM_IMPL_POSIX: return true; case DSM_IMPL_SYSV: diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 9e39baf466..657c3f81f8 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -133,7 +133,6 @@ # sysv # windows # mmap - # use none to disable dynamic shared memory # (change requires restart) # - Disk - diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c index ae22e7d9fb..3f203c6ca6 100644 --- a/src/bin/initdb/initdb.c +++ b/src/bin/initdb/initdb.c @@ -984,6 +984,15 @@ test_config_settings(void) ok_buffers = 0; + /* + * Need to determine working DSM implementation first so that subsequent + * tests don't fail because DSM setting doesn't work. + */ + printf(_("selecting dynamic shared memory implementation ... ")); + fflush(stdout); + dynamic_shared_memory_type = choose_dsm_implementation(); + printf("%s\n", dynamic_shared_memory_type); + printf(_("selecting default max_connections ... ")); fflush(stdout); @@ -996,10 +1005,11 @@ test_config_settings(void) "\"%s\" --boot -x0 %s " "-c max_connections=%d " "-c shared_buffers=%d " - "-c dynamic_shared_memory_type=none " + "-c dynamic_shared_memory_type=%s " "< \"%s\" > \"%s\" 2>&1", backend_exec, boot_options, test_conns, test_buffs, + dynamic_shared_memory_type, DEVNULL, DEVNULL); status = system(cmd); if (status == 0) @@ -1031,10 +1041,11 @@ test_config_settings(void) "\"%s\" --boot -x0 %s " "-c max_connections=%d " "-c shared_buffers=%d " - "-c dynamic_shared_memory_type=none " + "-c dynamic_shared_memory_type=%s " "< \"%s\" > \"%s\" 2>&1", backend_exec, boot_options, n_connections, test_buffs, + dynamic_shared_memory_type, DEVNULL, DEVNULL); status = system(cmd); if (status == 0) @@ -1046,11 +1057,6 @@ test_config_settings(void) printf("%dMB\n", (n_buffers * (BLCKSZ / 1024)) / 1024); else printf("%dkB\n", n_buffers * (BLCKSZ / 1024)); - - printf(_("selecting dynamic shared memory implementation ... ")); - fflush(stdout); - dynamic_shared_memory_type = choose_dsm_implementation(); - printf("%s\n", dynamic_shared_memory_type); } /* diff --git a/src/include/storage/dsm_impl.h b/src/include/storage/dsm_impl.h index 0e5730f7c5..e7acdff355 100644 --- a/src/include/storage/dsm_impl.h +++ b/src/include/storage/dsm_impl.h @@ -14,7 +14,6 @@ #define DSM_IMPL_H /* Dynamic shared memory implementations. */ -#define DSM_IMPL_NONE 0 #define DSM_IMPL_POSIX 1 #define DSM_IMPL_SYSV 2 #define DSM_IMPL_WINDOWS 3