*** a/src/backend/access/nbtree/nbtutils.c --- b/src/backend/access/nbtree/nbtutils.c *************** *** 21,26 **** --- 21,27 ---- #include "access/reloptions.h" #include "access/relscan.h" #include "miscadmin.h" + #include "storage/proc.h" #include "utils/array.h" #include "utils/lsyscache.h" #include "utils/memutils.h" *** a/src/backend/access/transam/multixact.c --- b/src/backend/access/transam/multixact.c *************** *** 57,62 **** --- 57,63 ---- #include "miscadmin.h" #include "pg_trace.h" #include "storage/lmgr.h" + #include "storage/proc.h" #include "storage/procarray.h" #include "utils/builtins.h" #include "utils/memutils.h" *** a/src/backend/commands/async.c --- b/src/backend/commands/async.c *************** *** 126,131 **** --- 126,132 ---- #include "miscadmin.h" #include "storage/ipc.h" #include "storage/lmgr.h" + #include "storage/proc.h" #include "storage/procsignal.h" #include "storage/sinval.h" #include "tcop/tcopprot.h" *** a/src/backend/libpq/pqcomm.c --- b/src/backend/libpq/pqcomm.c *************** *** 93,98 **** --- 93,99 ---- #include "libpq/libpq.h" #include "miscadmin.h" #include "storage/ipc.h" + #include "storage/proc.h" #include "utils/guc.h" #include "utils/memutils.h" *** a/src/backend/postmaster/autovacuum.c --- b/src/backend/postmaster/autovacuum.c *************** *** 108,114 **** * GUC parameters */ bool autovacuum_start_daemon = false; ! int autovacuum_max_workers; int autovacuum_naptime; int autovacuum_vac_thresh; double autovacuum_vac_scale; --- 108,114 ---- * GUC parameters */ bool autovacuum_start_daemon = false; ! /* autovacuum_max_workers is elsewhere */ int autovacuum_naptime; int autovacuum_vac_thresh; double autovacuum_vac_scale; *** a/src/backend/postmaster/pgstat.c --- b/src/backend/postmaster/pgstat.c *************** *** 52,57 **** --- 52,58 ---- #include "storage/ipc.h" #include "storage/latch.h" #include "storage/pg_shmem.h" + #include "storage/proc.h" #include "storage/procsignal.h" #include "utils/ascii.h" #include "utils/guc.h" *** a/src/backend/postmaster/postmaster.c --- b/src/backend/postmaster/postmaster.c *************** *** 897,913 **** PostmasterMain(int argc, char *argv[]) process_shared_preload_libraries(); /* - * If loadable modules have added background workers, MaxBackends needs to - * be updated. Do so now by forcing a no-op update of max_connections. - * XXX This is a pretty ugly way to do it, but it doesn't seem worth - * introducing a new entry point in guc.c to do it in a cleaner fashion. - */ - if (GetNumShmemAttachedBgworkers() > 0) - SetConfigOption("max_connections", - GetConfigOption("max_connections", false, false), - PGC_POSTMASTER, PGC_S_OVERRIDE); - - /* * Establish input sockets. */ for (i = 0; i < MAXLISTEN; i++) --- 897,902 ---- *************** *** 5176,5181 **** RegisterBackgroundWorker(BackgroundWorker *worker) --- 5165,5180 ---- return; } + if (MaxBackends >= MAX_BACKENDS) + { + ereport(LOG, + (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED), + errmsg("too many background workers"), + errhint("max_connections plus autovacuum_max_workers plus the total number of background workers cannot exceed %d", + MAX_BACKENDS - 1))); + return; + } + /* sanity check for flags */ if (worker->bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION) { *** a/src/backend/storage/ipc/procsignal.c --- b/src/backend/storage/ipc/procsignal.c *************** *** 21,26 **** --- 21,27 ---- #include "miscadmin.h" #include "storage/latch.h" #include "storage/ipc.h" + #include "storage/proc.h" #include "storage/shmem.h" #include "storage/sinval.h" #include "tcop/tcopprot.h" *** a/src/backend/utils/init/globals.c --- b/src/backend/utils/init/globals.c *************** *** 103,115 **** int work_mem = 1024; int maintenance_work_mem = 16384; /* ! * Primary determinants of sizes of shared-memory structures. MaxBackends is ! * MaxConnections + autovacuum_max_workers + 1 (it is computed by the GUC ! * assign hooks for those variables): */ int NBuffers = 1000; - int MaxBackends = 100; int MaxConnections = 90; int VacuumCostPageHit = 1; /* GUC parameters for vacuum */ int VacuumCostPageMiss = 10; --- 103,113 ---- int maintenance_work_mem = 16384; /* ! * Primary determinants of sizes of shared-memory structures. */ int NBuffers = 1000; int MaxConnections = 90; + int autovacuum_max_workers = 3; int VacuumCostPageHit = 1; /* GUC parameters for vacuum */ int VacuumCostPageMiss = 10; *** a/src/backend/utils/misc/guc.c --- b/src/backend/utils/misc/guc.c *************** *** 103,118 **** #define MAX_KILOBYTES (INT_MAX / 1024) #endif - /* - * Note: MAX_BACKENDS is limited to 2^23-1 because inval.c stores the - * backend ID as a 3-byte signed integer. Even if that limitation were - * removed, we still could not exceed INT_MAX/4 because some places compute - * 4*MaxBackends without any overflow check. This is rechecked in - * check_maxconnections, since MaxBackends is computed as MaxConnections - * plus the number of bgworkers plus autovacuum_max_workers plus one (for the - * autovacuum launcher). - */ - #define MAX_BACKENDS 0x7fffff #define KB_PER_MB (1024) #define KB_PER_GB (1024*1024) --- 103,108 ---- *************** *** 199,207 **** static const char *show_tcp_keepalives_idle(void); static const char *show_tcp_keepalives_interval(void); static const char *show_tcp_keepalives_count(void); static bool check_maxconnections(int *newval, void **extra, GucSource source); - static void assign_maxconnections(int newval, void *extra); static bool check_autovacuum_max_workers(int *newval, void **extra, GucSource source); - static void assign_autovacuum_max_workers(int newval, void *extra); static bool check_effective_io_concurrency(int *newval, void **extra, GucSource source); static void assign_effective_io_concurrency(int newval, void *extra); static void assign_pgstat_temp_directory(const char *newval, void *extra); --- 189,195 ---- *************** *** 1615,1621 **** static struct config_int ConfigureNamesInt[] = }, &MaxConnections, 100, 1, MAX_BACKENDS, ! check_maxconnections, assign_maxconnections, NULL }, { --- 1603,1609 ---- }, &MaxConnections, 100, 1, MAX_BACKENDS, ! check_maxconnections, NULL, NULL }, { *************** *** 2290,2296 **** static struct config_int ConfigureNamesInt[] = }, &autovacuum_max_workers, 3, 1, MAX_BACKENDS, ! check_autovacuum_max_workers, assign_autovacuum_max_workers, NULL }, { --- 2278,2284 ---- }, &autovacuum_max_workers, 3, 1, MAX_BACKENDS, ! check_autovacuum_max_workers, NULL, NULL }, { *************** *** 8630,8648 **** show_tcp_keepalives_count(void) static bool check_maxconnections(int *newval, void **extra, GucSource source) { ! if (*newval + GetNumShmemAttachedBgworkers() + autovacuum_max_workers + 1 > MAX_BACKENDS) return false; return true; } - static void - assign_maxconnections(int newval, void *extra) - { - MaxBackends = newval + autovacuum_max_workers + 1 + - GetNumShmemAttachedBgworkers(); - } - static bool check_autovacuum_max_workers(int *newval, void **extra, GucSource source) { --- 8618,8629 ---- static bool check_maxconnections(int *newval, void **extra, GucSource source) { ! if (*newval + autovacuum_max_workers + 1 + GetNumShmemAttachedBgworkers() > MAX_BACKENDS) return false; return true; } static bool check_autovacuum_max_workers(int *newval, void **extra, GucSource source) { *************** *** 8652,8663 **** check_autovacuum_max_workers(int *newval, void **extra, GucSource source) return true; } - static void - assign_autovacuum_max_workers(int newval, void *extra) - { - MaxBackends = MaxConnections + newval + 1 + GetNumShmemAttachedBgworkers(); - } - static bool check_effective_io_concurrency(int *newval, void **extra, GucSource source) { --- 8633,8638 ---- *** a/src/include/miscadmin.h --- b/src/include/miscadmin.h *************** *** 139,146 **** extern bool ExitOnAnyError; extern PGDLLIMPORT char *DataDir; extern PGDLLIMPORT int NBuffers; - extern int MaxBackends; - extern int MaxConnections; extern PGDLLIMPORT int MyProcPid; extern PGDLLIMPORT pg_time_t MyStartTime; --- 139,144 ---- *** a/src/include/postmaster/autovacuum.h --- b/src/include/postmaster/autovacuum.h *************** *** 17,23 **** /* GUC variables */ extern bool autovacuum_start_daemon; ! extern int autovacuum_max_workers; extern int autovacuum_naptime; extern int autovacuum_vac_thresh; extern double autovacuum_vac_scale; --- 17,23 ---- /* GUC variables */ extern bool autovacuum_start_daemon; ! /* autovacuum_max_workers is elsewhere */ extern int autovacuum_naptime; extern int autovacuum_vac_thresh; extern double autovacuum_vac_scale; *** a/src/include/storage/proc.h --- b/src/include/storage/proc.h *************** *** 15,24 **** --- 15,43 ---- #define _PROC_H_ #include "access/xlogdefs.h" + #include "postmaster/postmaster.h" #include "storage/latch.h" #include "storage/lock.h" #include "storage/pg_sema.h" + + /* + * GUC variables determining the maximum number of backend processes. + */ + extern int MaxConnections; + extern int autovacuum_max_workers; + #define MaxBackends (MaxConnections + autovacuum_max_workers + 1 + \ + GetNumShmemAttachedBgworkers()) + /* + * Note: MAX_BACKENDS is limited to 2^23-1 because inval.c stores the + * backend ID as a 3-byte signed integer. Even if that limitation were + * removed, we still could not exceed INT_MAX/4 because some places compute + * 4*MaxBackends without any overflow check. This is rechecked in + * check_maxconnections and check_autovacuum_max_workers, and also in the + * background worker registration code. + */ + #define MAX_BACKENDS 0x7fffff + /* * Each backend advertises up to PGPROC_MAX_CACHED_SUBXIDS TransactionIds * for non-aborted subtransactions of its current top transaction. These