Hmm, seems --disable-spinlocks has been broken for awhile and nobody

tglsfdc · tglsfdc · commit c0e9b3139fe2 · 2006-07-22T21:04:40.000Z
noticed.  Fix SpinlockSemas() to report the correct count considering
that PG 8.1 adds a spinlock to each shared-buffer header.
diff --git a/src/backend/storage/lmgr/spin.c b/src/backend/storage/lmgr/spin.c
@@ -16,12 +16,14 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/spin.c,v 1.20 2006/07/14 14:52:23 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/spin.c,v 1.21 2006/07/22 21:04:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
+#include "miscadmin.h"
+#include "storage/lwlock.h"
 #include "storage/spin.h"
 
 
@@ -53,9 +55,9 @@ SpinlockSemas(void)
 	 * similar to the way shmem space estimation is handled.
 	 *
 	 * For now, though, we just need a few spinlocks (10 should be plenty)
-	 * plus one for each LWLock.
+	 * plus one for each LWLock and one for each buffer header.
 	 */
-	return NumLWLocks() + 10;
+	return NumLWLocks() + NBuffers + 10;
 }
 
 /*

Original file line number	Diff line number	Diff line change
`@@ -16,12 +16,14 @@`
`16`	`16`	`*`
`17`	`17`	`*`
`18`	`18`	`* IDENTIFICATION`
`19`		`- * $PostgreSQL: pgsql/src/backend/storage/lmgr/spin.c,v 1.20 2006/07/14 14:52:23 momjian Exp $`
	`19`	`+ * $PostgreSQL: pgsql/src/backend/storage/lmgr/spin.c,v 1.21 2006/07/22 21:04:40 tgl Exp $`
`20`	`20`	`*`
`21`	`21`	`*-------------------------------------------------------------------------`
`22`	`22`	`*/`
`23`	`23`	`#include "postgres.h"`
`24`	`24`
	`25`	`+#include "miscadmin.h"`
	`26`	`+#include "storage/lwlock.h"`
`25`	`27`	`#include "storage/spin.h"`
`26`	`28`
`27`	`29`
`@@ -53,9 +55,9 @@ SpinlockSemas(void)`
`53`	`55`	`* similar to the way shmem space estimation is handled.`
`54`	`56`	`*`
`55`	`57`	`* For now, though, we just need a few spinlocks (10 should be plenty)`
`56`		`- * plus one for each LWLock.`
	`58`	`+ * plus one for each LWLock and one for each buffer header.`
`57`	`59`	`*/`
`58`		`- return NumLWLocks() + 10;`
	`60`	`+ return NumLWLocks() + NBuffers + 10;`
`59`	`61`	`}`
`60`	`62`
`61`	`63`	`/*`