From 731603a92b115db97c1202df243954195070c500 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 6 Mar 1999 21:17:56 +0000
Subject: [PATCH] A few further tweaks to shared memory space estimation. This
change brings the default size of the main shmem block back under 1MB, which
is a fairly popular value for the kernel's SHMMAX parameter.
---
src/backend/storage/ipc/ipci.c | 4 +---
src/backend/storage/lmgr/lock.c | 23 ++++++++++++++---------
src/backend/storage/smgr/mm.c | 6 +++---
src/backend/utils/hash/dynahash.c | 26 +++++++++++++++++---------
src/include/storage/lock.h | 10 +++++++---
5 files changed, 42 insertions(+), 27 deletions(-)
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 2f5d1d3a193..e7d6e702bf2 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipci.c,v 1.22 1999/02/22 06:16:49 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipci.c,v 1.23 1999/03/06 21:17:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -77,14 +77,12 @@ CreateSharedMemoryAndSemaphores(IPCKey key, int maxBackends)
* Size of the primary shared-memory block is estimated via
* moderately-accurate estimates for the big hogs, plus 100K for
* the stuff that's too small to bother with estimating.
- * Then we add 10% for a safety margin.
*/
size = BufferShmemSize() + LockShmemSize(maxBackends);
#ifdef STABLE_MEMORY_STORAGE
size += MMShmemSize();
#endif
size += 100000;
- size += size / 10;
if (DebugLvl > 1)
{
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index ed9a5b31313..2f822add66d 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.45 1999/02/22 06:16:52 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.46 1999/03/06 21:17:44 tgl Exp $
*
* NOTES
* Outside modules can create a lock table and acquire/release
@@ -339,8 +339,8 @@ LockMethodTableInit(char *tabName,
* to find the different locks.
* ----------------------
*/
- info.keysize = sizeof(LOCKTAG);
- info.datasize = sizeof(LOCK);
+ info.keysize = SHMEM_LOCKTAB_KEYSIZE;
+ info.datasize = SHMEM_LOCKTAB_DATASIZE;
info.hash = tag_hash;
hash_flags = (HASH_ELEM | HASH_FUNCTION);
@@ -361,8 +361,8 @@ LockMethodTableInit(char *tabName,
* the same lock, additional information must be saved (locks per tx).
* -------------------------
*/
- info.keysize = XID_TAGSIZE;
- info.datasize = sizeof(XIDLookupEnt);
+ info.keysize = SHMEM_XIDTAB_KEYSIZE;
+ info.datasize = SHMEM_XIDTAB_DATASIZE;
info.hash = tag_hash;
hash_flags = (HASH_ELEM | HASH_FUNCTION);
@@ -1488,13 +1488,18 @@ LockShmemSize(int maxBackends)
/* lockHash table */
size += hash_estimate_size(NLOCKENTS(maxBackends),
- sizeof(LOCKTAG),
- sizeof(LOCK));
+ SHMEM_LOCKTAB_KEYSIZE,
+ SHMEM_LOCKTAB_DATASIZE);
/* xidHash table */
size += hash_estimate_size(maxBackends,
- XID_TAGSIZE,
- sizeof(XIDLookupEnt));
+ SHMEM_XIDTAB_KEYSIZE,
+ SHMEM_XIDTAB_DATASIZE);
+
+ /* Since the lockHash entry count above is only an estimate,
+ * add 10% safety margin.
+ */
+ size += size / 10;
return size;
}
diff --git a/src/backend/storage/smgr/mm.c b/src/backend/storage/smgr/mm.c
index 603ee590638..2d5c1cdc4d8 100644
--- a/src/backend/storage/smgr/mm.c
+++ b/src/backend/storage/smgr/mm.c
@@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/smgr/Attic/mm.c,v 1.14 1999/02/22 06:16:57 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/smgr/Attic/mm.c,v 1.15 1999/03/06 21:17:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -110,7 +110,7 @@ mminit()
}
info.keysize = sizeof(MMCacheTag);
- info.datasize = sizeof(int);
+ info.datasize = sizeof(MMHashEntry) - sizeof(MMCacheTag);
info.hash = tag_hash;
MMCacheHT = (HTAB *) ShmemInitHash("Main memory store HT",
@@ -124,7 +124,7 @@ mminit()
}
info.keysize = sizeof(MMRelTag);
- info.datasize = sizeof(int);
+ info.datasize = sizeof(MMRelHashEntry) - sizeof(MMRelTag);
info.hash = tag_hash;
MMRelCacheHT = (HTAB *) ShmemInitHash("Main memory rel HT",
diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c
index dcf4e4cce55..f9d87120535 100644
--- a/src/backend/utils/hash/dynahash.c
+++ b/src/backend/utils/hash/dynahash.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/hash/dynahash.c,v 1.19 1999/02/22 06:16:47 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/hash/dynahash.c,v 1.20 1999/03/06 21:17:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -373,18 +373,23 @@ hash_estimate_size(long num_entries, long keysize, long datasize)
long size = 0;
long nBuckets,
nSegments,
+ nDirEntries,
nRecordAllocs,
recordSize;
/* estimate number of buckets wanted */
nBuckets = 1L << my_log2((num_entries - 1) / DEF_FFACTOR + 1);
/* # of segments needed for nBuckets */
- nSegments = (nBuckets - 1) / DEF_SEGSIZE + 1;
+ nSegments = 1L << my_log2((nBuckets - 1) / DEF_SEGSIZE + 1);
+ /* directory entries */
+ nDirEntries = DEF_DIRSIZE;
+ while (nDirEntries < nSegments)
+ nDirEntries <<= 1; /* dir_alloc doubles dsize at each call */
/* fixed control info */
size += MAXALIGN(sizeof(HHDR)); /* but not HTAB, per above */
- /* directory, assumed to be of size DEF_DIRSIZE */
- size += MAXALIGN(DEF_DIRSIZE * sizeof(SEG_OFFSET));
+ /* directory */
+ size += MAXALIGN(nDirEntries * sizeof(SEG_OFFSET));
/* segments */
size += nSegments * MAXALIGN(DEF_SEGSIZE * sizeof(BUCKET_INDEX));
/* records --- allocated in groups of BUCKET_ALLOC_INCR */
@@ -408,9 +413,6 @@ hash_estimate_size(long num_entries, long keysize, long datasize)
void
hash_destroy(HTAB *hashp)
{
- /* cannot destroy a shared memory hash table */
- Assert(!hashp->segbase);
-
if (hashp != NULL)
{
SEG_OFFSET segNum;
@@ -422,6 +424,13 @@ hash_destroy(HTAB *hashp)
q;
ELEMENT *curr;
+ /* cannot destroy a shared memory hash table */
+ Assert(!hashp->segbase);
+ /* allocation method must be one we know how to free, too */
+ Assert(hashp->alloc == (dhalloc_ptr) MEM_ALLOC);
+
+ hash_stats("destroy", hashp);
+
for (segNum = 0; nsegs > 0; nsegs--, segNum++)
{
@@ -435,11 +444,10 @@ hash_destroy(HTAB *hashp)
MEM_FREE((char *) curr);
}
}
- free((char *) segp);
+ MEM_FREE((char *) segp);
}
MEM_FREE((char *) hashp->dir);
MEM_FREE((char *) hashp->hctl);
- hash_stats("destroy", hashp);
MEM_FREE((char *) hashp);
}
}
diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
index ce1f30133f3..da77f1d523c 100644
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: lock.h,v 1.23 1999/02/21 01:41:47 tgl Exp $
+ * $Id: lock.h,v 1.24 1999/03/06 21:17:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -57,8 +57,6 @@ typedef int LOCKMETHOD;
#define USER_LOCKMETHOD 2
#define MIN_LOCKMETHOD DEFAULT_LOCKMETHOD
-/*typedef struct LOCK LOCK; */
-
typedef struct LTAG
{
@@ -174,6 +172,9 @@ typedef struct XIDLookupEnt
SHM_QUEUE queue;
} XIDLookupEnt;
+#define SHMEM_XIDTAB_KEYSIZE sizeof(XIDTAG)
+#define SHMEM_XIDTAB_DATASIZE (sizeof(XIDLookupEnt) - SHMEM_XIDTAB_KEYSIZE)
+
#define XID_TAGSIZE (sizeof(XIDTAG))
#define XIDENT_LOCKMETHOD(xident) (XIDTAG_LOCKMETHOD((xident).tag))
@@ -210,6 +211,9 @@ typedef struct LOCK
int nActive;
} LOCK;
+#define SHMEM_LOCKTAB_KEYSIZE sizeof(LOCKTAG)
+#define SHMEM_LOCKTAB_DATASIZE (sizeof(LOCK) - SHMEM_LOCKTAB_KEYSIZE)
+
#define LOCK_LOCKMETHOD(lock) (LOCKTAG_LOCKMETHOD((lock).tag))
#define LockGetLock_nHolders(l) l->nHolders
--
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