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The default values for shared_buffers and max_connections are now 1000

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and 100 respectively, if the platform will allow it.  initdb selects
values that are not too large to allow the postmaster to start, and
places these values in the installed postgresql.conf file.  This allows
us to continue to start up out-of-the-box on platforms with small SHMMAX,
while having somewhat-realistic default settings on platforms with
reasonable SHMMAX.  Per recent pghackers discussion.
This commit is contained in:
Tom Lane
2003-07-14 20:00:23 +00:00
parent 8460000069
commit de98a7e23a
5 changed files with 97 additions and 88 deletions
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86
src/backend/port/sysv_shmem.c
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@ -10,7 +10,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/port/sysv_shmem.c,v 1.10 2003/05/08 19:17:07 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/port/sysv_shmem.c,v 1.11 2003/07/14 20:00:22 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -45,10 +45,8 @@ void *UsedShmemSegAddr = NULL;
static void *InternalIpcMemoryCreate(IpcMemoryKey memKey, uint32 size);
static void IpcMemoryDetach(int status, Datum shmaddr);
static void IpcMemoryDelete(int status, Datum shmId);
static void *PrivateMemoryCreate(uint32 size);
static void PrivateMemoryDelete(int status, Datum memaddr);
static PGShmemHeader *PGSharedMemoryAttach(IpcMemoryKey key,
IpcMemoryId *shmid, void *addr);
IpcMemoryId *shmid);
/*
@ -243,41 +241,6 @@ PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2)
}
/* ----------------------------------------------------------------
* private memory support
*
* Rather than allocating shmem segments with IPC_PRIVATE key, we
* just malloc() the requested amount of space. This code emulates
* the needed shmem functions.
* ----------------------------------------------------------------
*/
static void *
PrivateMemoryCreate(uint32 size)
{
void *memAddress;
memAddress = malloc(size);
if (!memAddress)
{
fprintf(stderr, "PrivateMemoryCreate: malloc(%u) failed\n", size);
proc_exit(1);
}
MemSet(memAddress, 0, size); /* keep Purify quiet */
/* Register on-exit routine to release storage */
on_shmem_exit(PrivateMemoryDelete, PointerGetDatum(memAddress));
return memAddress;
}
static void
PrivateMemoryDelete(int status, Datum memaddr)
{
free(DatumGetPointer(memaddr));
}
/*
* PGSharedMemoryCreate
*
@ -289,6 +252,9 @@ PrivateMemoryDelete(int status, Datum memaddr)
* collision with non-Postgres shmem segments. The idea here is to detect and
* re-use keys that may have been assigned by a crashed postmaster or backend.
*
* makePrivate means to always create a new segment, rather than attach to
* or recycle any existing segment.
*
* The port number is passed for possible use as a key (for SysV, we use
* it to generate the starting shmem key). In a standalone backend,
* zero will be passed.
@ -307,8 +273,7 @@ PGSharedMemoryCreate(uint32 size, bool makePrivate, int port)
/* Just attach and return the pointer */
if (ExecBackend && UsedShmemSegAddr != NULL && !makePrivate)
{
if ((hdr = (PGShmemHeader *) memAddress = PGSharedMemoryAttach(
UsedShmemSegID, &shmid, UsedShmemSegAddr)) == NULL)
if ((hdr = PGSharedMemoryAttach(UsedShmemSegID, &shmid)) == NULL)
{
fprintf(stderr, "Unable to attach to proper memory at fixed address: shmget(key=%d, addr=%p) failed: %s\n",
(int) UsedShmemSegID, UsedShmemSegAddr, strerror(errno));
@ -317,34 +282,29 @@ PGSharedMemoryCreate(uint32 size, bool makePrivate, int port)
return hdr;
}
/* Create shared memory */
NextShmemSegID = port * 1000 + 1;
/* Loop till we find a free IPC key */
NextShmemSegID = port * 1000;
for (;;NextShmemSegID++)
for (NextShmemSegID++;; NextShmemSegID++)
{
/* Special case if creating a private segment --- just malloc() it */
if (makePrivate)
{
memAddress = PrivateMemoryCreate(size);
break;
}
/* Try to create new segment */
memAddress = InternalIpcMemoryCreate(NextShmemSegID, size);
if (memAddress)
break; /* successful create and attach */
/* Check shared memory and possibly remove and recreate */
if ((hdr = (PGShmemHeader *) memAddress = PGSharedMemoryAttach(
NextShmemSegID, &shmid, UsedShmemSegAddr)) == NULL)
if (makePrivate) /* a standalone backend shouldn't do this */
continue;
if ((memAddress = PGSharedMemoryAttach(NextShmemSegID, &shmid)) == NULL)
continue; /* can't attach, not one of mine */
/*
* If I am not the creator and it belongs to an extant process,
* continue.
*/
hdr = (PGShmemHeader *) memAddress;
if (hdr->creatorPID != getpid())
{
if (kill(hdr->creatorPID, 0) == 0 || errno != ESRCH)
@ -407,22 +367,25 @@ PGSharedMemoryCreate(uint32 size, bool makePrivate, int port)
/*
* Attach to shared memory and make sure it has a Postgres header
* Attach to shared memory and make sure it has a Postgres header
*
* Returns attach address if OK, else NULL
*/
static PGShmemHeader *
PGSharedMemoryAttach(IpcMemoryKey key, IpcMemoryId *shmid, void *addr)
PGSharedMemoryAttach(IpcMemoryKey key, IpcMemoryId *shmid)
{
PGShmemHeader *hdr;
if ((*shmid = shmget(key, sizeof(PGShmemHeader), 0)) < 0)
return NULL;
hdr = (PGShmemHeader *) shmat(*shmid, UsedShmemSegAddr,
hdr = (PGShmemHeader *) shmat(*shmid,
UsedShmemSegAddr,
#if defined(solaris) && defined(__sparc__)
/* use intimate shared memory on SPARC Solaris */
SHM_SHARE_MMU
/* use intimate shared memory on Solaris */
SHM_SHARE_MMU
#else
0
0
#endif
);
@ -434,5 +397,6 @@ PGSharedMemoryAttach(IpcMemoryKey key, IpcMemoryId *shmid, void *addr)
shmdt(hdr);
return NULL; /* segment belongs to a non-Postgres app */
}
return hdr;
}