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Rearrange handling of MAXBACKENDS a little bit. The default setting

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of MAXBACKENDS is now 1024, since all it's costing is about 32 bytes of memory
per array slot.  configure's --with-maxbackends switch now controls DEF_MAXBACKENDS
which is simply the default value of the postmaster's -N switch.  Thus,
the out-of-the-box configuration will still limit you to 64 backends,
but you can go up to 1024 backends simply by restarting the postmaster with
a different -N switch --- no rebuild required.
This commit is contained in:
Tom Lane
1999-02-21 01:41:55 +00:00
parent 75cccd0ad3
commit 9d197856dd
10 changed files with 78 additions and 67 deletions
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39
src/backend/storage/lmgr/proc.c
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@ -7,7 +7,7 @@
*
*
* 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 $
*
*-------------------------------------------------------------------------
*/
@ -46,7 +46,7 @@
* 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>
@ -154,23 +154,28 @@ InitProcGlobal(IPCKey key, int maxBackends)
*/
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;
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);
semId = IpcSemaphoreCreate(semKey,
PROC_NSEMS_PER_SET,
IPCProtection,
IpcSemaphoreDefaultStartValue,
0,
&semstat);
/* mark this sema set allocated */
ProcGlobal->freeSemMap[i] = (1 << PROC_NSEMS_PER_SET);
}
}
}
}