*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.102 1999/02/19 06:06:00 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.103 1999/02/21 01:41:43 tgl Exp $
*
* NOTES
*
* adding to this.
*/
-static int MaxBackends = MAXBACKENDS;
+static int MaxBackends = DEF_MAXBACKENDS;
/*
- * MaxBackends is the actual soft limit on the number of backends
- * we will start. It defaults to the hard limit established at compilation
- * time, but can be readjusted with postmaster's xxx switch.
- * One reason to reduce MaxBackends is to allow startup under a kernel
- * that won't let us get MAXBACKENDS semaphores!
+ * MaxBackends is the actual limit on the number of backends we will start.
+ * The default is established by configure, but it can be readjusted
+ * from 1..MAXBACKENDS with the postmaster -N switch.
+ * Note that a larger MaxBackends value will increase the size of the
+ * shared memory area as well as cause the postmaster to grab more
+ * kernel semaphores, even if you never actually use that many backends.
*/
static int NextBackendTag = MAXINT; /* XXX why count down not up? */
fprintf(stderr, "\t-b backend\tuse a specific backend server executable\n");
fprintf(stderr, "\t-d [1|2|3]\tset debugging level\n");
fprintf(stderr, "\t-i \t\tlisten on TCP/IP sockets as well as Unix domain socket\n");
- fprintf(stderr, "\t-N nprocs\tset max number of backend servers (1..%d)\n",
- MAXBACKENDS);
+ fprintf(stderr, "\t-N nprocs\tset max number of backends (1..%d, default %d)\n",
+ MAXBACKENDS, DEF_MAXBACKENDS);
fprintf(stderr, "\t-n \t\tdon't reinitialize shared memory after abnormal exit\n");
fprintf(stderr, "\t-o option\tpass 'option' to each backend servers\n");
fprintf(stderr, "\t-p port\tspecify port for postmaster to listen on\n");
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipc.c,v 1.35 1999/02/13 23:18:09 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipc.c,v 1.36 1999/02/21 01:41:44 tgl Exp $
*
* NOTES
*
SLock *free;
int unused;
slock_t memlock;
- SLock slocks[NSLOCKS];
+ SLock slocks[MAX_SPINS + 1];
};
-static int SLockMemorySize = sizeof(struct ipcdummy);
+
+#define SLOCKMEMORYSIZE sizeof(struct ipcdummy)
void
CreateAndInitSLockMemory(IPCKey key)
SLock *slckP;
SLockMemoryId = IpcMemoryCreate(key,
- SLockMemorySize,
+ SLOCKMEMORYSIZE,
0700);
AttachSLockMemory(key);
*FreeSLockPP = NULL;
struct ipcdummy *slockM;
if (SLockMemoryId == -1)
- SLockMemoryId = IpcMemoryIdGet(key, SLockMemorySize);
+ SLockMemoryId = IpcMemoryIdGet(key, SLOCKMEMORYSIZE);
if (SLockMemoryId == -1)
elog(FATAL, "SLockMemory not in shared memory");
slockM = (struct ipcdummy *) IpcMemoryAttach(SLockMemoryId);
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipci.c,v 1.20 1999/02/19 07:10:47 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipci.c,v 1.21 1999/02/21 01:41:44 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* ----------------
*/
CreateSpinlocks(IPCKeyGetSpinLockSemaphoreKey(key));
- size = BufferShmemSize() + LockShmemSize();
+ size = BufferShmemSize() + LockShmemSize(maxBackends);
#ifdef STABLE_MEMORY_STORAGE
size += MMShmemSize();
void
AttachSharedMemoryAndSemaphores(IPCKey key)
{
- int size;
-
/* ----------------
* create rather than attach if using private key
* ----------------
*/
if (key == PrivateIPCKey)
{
- CreateSharedMemoryAndSemaphores(key, 1);
+ CreateSharedMemoryAndSemaphores(key, 16);
return;
}
* attach the buffer manager buffer pool (and semaphore)
* ----------------
*/
- size = BufferShmemSize() + LockShmemSize();
- InitShmem(key, size);
+ InitShmem(key, 0);
InitBufferPool(key);
/* ----------------
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.42 1999/02/19 06:06:06 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.43 1999/02/21 01:41:46 tgl Exp $
*
* NOTES
* Outside modules can create a lock table and acquire/release
}
int
-LockShmemSize()
+LockShmemSize(int maxBackends)
{
int size = 0;
+ int nLockEnts = NLOCKENTS(maxBackends);
int nLockBuckets,
nLockSegs;
int nXidBuckets,
nXidSegs;
- nLockBuckets = 1 << (int) my_log2((NLOCKENTS - 1) / DEF_FFACTOR + 1);
+ nLockBuckets = 1 << (int) my_log2((nLockEnts - 1) / DEF_FFACTOR + 1);
nLockSegs = 1 << (int) my_log2((nLockBuckets - 1) / DEF_SEGSIZE + 1);
nXidBuckets = 1 << (int) my_log2((NLOCKS_PER_XACT - 1) / DEF_FFACTOR + 1);
nXidSegs = 1 << (int) my_log2((nLockBuckets - 1) / DEF_SEGSIZE + 1);
- size += MAXALIGN(MAXBACKENDS * sizeof(PROC)); /* each MyProc */
- size += MAXALIGN(MAXBACKENDS * sizeof(LOCKMETHODCTL)); /* each
+ size += MAXALIGN(maxBackends * sizeof(PROC)); /* each MyProc */
+ size += MAXALIGN(maxBackends * sizeof(LOCKMETHODCTL)); /* each
* lockMethodTable->ctl */
size += MAXALIGN(sizeof(PROC_HDR)); /* ProcGlobal */
- size += MAXALIGN(my_log2(NLOCKENTS) * sizeof(void *));
+ size += MAXALIGN(my_log2(nLockEnts) * sizeof(void *));
size += MAXALIGN(sizeof(HHDR));
size += nLockSegs * MAXALIGN(DEF_SEGSIZE * sizeof(SEGMENT));
- size += NLOCKENTS * /* XXX not multiple of BUCKET_ALLOC_INCR? */
+ size += nLockEnts * /* XXX not multiple of BUCKET_ALLOC_INCR? */
(MAXALIGN(sizeof(BUCKET_INDEX)) +
MAXALIGN(sizeof(LOCK))); /* contains hash key */
- size += MAXALIGN(my_log2(MAXBACKENDS) * sizeof(void *));
+ size += MAXALIGN(my_log2(maxBackends) * sizeof(void *));
size += MAXALIGN(sizeof(HHDR));
size += nXidSegs * MAXALIGN(DEF_SEGSIZE * sizeof(SEGMENT));
- size += MAXBACKENDS * /* XXX not multiple of BUCKET_ALLOC_INCR? */
+ size += maxBackends * /* XXX not multiple of BUCKET_ALLOC_INCR? */
(MAXALIGN(sizeof(BUCKET_INDEX)) +
MAXALIGN(sizeof(XIDLookupEnt))); /* contains hash key */
break;
if (j >= nprocs && lock != findlock)
{
+ Assert(nprocs < MAXBACKENDS);
checked_procs[nprocs++] = proc;
- Assert(nprocs <= MAXBACKENDS);
/*
* For non-MyProc entries, we are looking only
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.50 1999/02/19 07:10:48 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.51 1999/02/21 01:41:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* This is so that we can support more backends. (system-wide semaphore
* sets run out pretty fast.) -ay 4/95
*
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.50 1999/02/19 07:10:48 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.51 1999/02/21 01:41:45 tgl Exp $
*/
#include <sys/time.h>
#include <unistd.h>
*/
on_shmem_exit(ProcFreeAllSemaphores, NULL);
- /* Pre-create the semaphores for the first maxBackends processes */
- for (i = 0;
- i < (maxBackends+PROC_NSEMS_PER_SET-1) / PROC_NSEMS_PER_SET;
- i++)
+ /* Pre-create the semaphores for the first maxBackends processes,
+ * unless we are running as a standalone backend.
+ */
+ if (key != PrivateIPCKey)
{
- IPCKey semKey = ProcGlobal->currKey + i;
- int semId;
- int semstat;
-
- semId = IpcSemaphoreCreate(semKey,
- PROC_NSEMS_PER_SET,
- IPCProtection,
- IpcSemaphoreDefaultStartValue,
- 0,
- &semstat);
- /* mark this sema set allocated */
- ProcGlobal->freeSemMap[i] = (1 << PROC_NSEMS_PER_SET);
+ for (i = 0;
+ i < (maxBackends+PROC_NSEMS_PER_SET-1) / PROC_NSEMS_PER_SET;
+ i++)
+ {
+ IPCKey semKey = ProcGlobal->currKey + i;
+ int semId;
+ int semstat;
+
+ semId = IpcSemaphoreCreate(semKey,
+ PROC_NSEMS_PER_SET,
+ IPCProtection,
+ IpcSemaphoreDefaultStartValue,
+ 0,
+ &semstat);
+ /* mark this sema set allocated */
+ ProcGlobal->freeSemMap[i] = (1 << PROC_NSEMS_PER_SET);
+ }
}
}
}
ac_help="$ac_help
--with-pgport=<portnum> change default startup port "
ac_help="$ac_help
- --with-maxbackends=<n> set maximum number of server processes "
+ --with-maxbackends=<n> set default maximum number of server processes "
ac_help="$ac_help
--with-tcl build Tcl interfaces and pgtclsh "
ac_help="$ac_help
fi
-echo $ac_n "checking setting MAXBACKENDS""... $ac_c" 1>&6
-echo "configure:884: checking setting MAXBACKENDS" >&5
+echo $ac_n "checking setting DEF_MAXBACKENDS""... $ac_c" 1>&6
+echo "configure:884: checking setting DEF_MAXBACKENDS" >&5
# Check whether --with-maxbackends or --without-maxbackends was given.
if test "${with_maxbackends+set}" = set; then
withval="$with_maxbackends"
cat >> confdefs.h <<EOF
-#define MAXBACKENDS ${withval}
+#define DEF_MAXBACKENDS ${withval}
EOF
echo "$ac_t""$with_maxbackends" 1>&6
else
cat >> confdefs.h <<EOF
-#define MAXBACKENDS 64
+#define DEF_MAXBACKENDS 64
EOF
echo "$ac_t""64" 1>&6
AC_DEFINE_UNQUOTED(DEF_PGPORT, "5432") AC_MSG_RESULT(5432)
)
-dnl MAXBACKENDS can be set by --with-maxbackends. Default value is 64.
-AC_MSG_CHECKING(setting MAXBACKENDS)
+dnl DEF_MAXBACKENDS can be set by --with-maxbackends. Default value is 64.
+AC_MSG_CHECKING(setting DEF_MAXBACKENDS)
AC_ARG_WITH(
maxbackends,
- [ --with-maxbackends=<n> set maximum number of server processes ],
- AC_DEFINE_UNQUOTED(MAXBACKENDS, ${withval}) AC_MSG_RESULT($with_maxbackends),
- AC_DEFINE_UNQUOTED(MAXBACKENDS, 64) AC_MSG_RESULT(64)
+ [ --with-maxbackends=<n> set default maximum number of server processes ],
+ AC_DEFINE_UNQUOTED(DEF_MAXBACKENDS, ${withval}) AC_MSG_RESULT($with_maxbackends),
+ AC_DEFINE_UNQUOTED(DEF_MAXBACKENDS, 64) AC_MSG_RESULT(64)
)
dnl We exclude tcl support unless user says --with-tcl
#define CONFIG_H
/*
- * Maximum number of backend server processes per postmaster.
+ * Default runtime limit on number of backend server processes per postmaster;
+ * this is just the default setting for the postmaster's -N switch.
* (Actual value is set by configure script.)
*/
-#undef MAXBACKENDS
+#undef DEF_MAXBACKENDS
+
+/*
+ * Hard limit on number of backend server processes per postmaster.
+ * Increasing this costs about 32 bytes per process slot as of v 6.5.
+ */
+#define MAXBACKENDS (DEF_MAXBACKENDS > 1024 ? DEF_MAXBACKENDS : 1024)
/*
* Size of a disk block --- currently, this limits the size of a tuple.
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: ipc.h,v 1.33 1999/02/19 06:06:33 tgl Exp $
+ * $Id: ipc.h,v 1.34 1999/02/21 01:41:47 tgl Exp $
*
* NOTES
* This file is very architecture-specific. This stuff should actually
#ifdef HAS_TEST_AND_SET
-#define NSLOCKS 2048
#define NOLOCK 0
#define SHAREDLOCK 1
#define EXCLUSIVELOCK 2
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: lock.h,v 1.22 1999/02/19 06:06:35 tgl Exp $
+ * $Id: lock.h,v 1.23 1999/02/21 01:41:47 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/* ----------------------
* The following defines are used to estimate how much shared
* memory the lock manager is going to require.
+ * See LockShmemSize() in lock.c.
*
- * MAXBACKENDS - The max number of concurrently running backends (config.h)
* NLOCKS_PER_XACT - The number of unique locks acquired in a transaction
* NLOCKENTS - The maximum number of lock entries in the lock table.
* ----------------------
*/
-#define NLOCKS_PER_XACT 40
-#define NLOCKENTS (NLOCKS_PER_XACT*MAXBACKENDS)
+#define NLOCKS_PER_XACT 40
+#define NLOCKENTS(maxBackends) (NLOCKS_PER_XACT*(maxBackends))
typedef int LOCKMODE;
typedef int LOCKMETHOD;
LOCKMODE lockmode);
extern void GrantLock(LOCK *lock, LOCKMODE lockmode);
extern bool LockReleaseAll(LOCKMETHOD lockmethod, SHM_QUEUE *lockQueue);
-extern int LockShmemSize(void);
+extern int LockShmemSize(int maxBackends);
extern bool LockingDisabled(void);
extern bool DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock,
bool skip_check);
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