Adjusted calculation of shared memory requirements to new

ARC buffer replacement strategy.

Jan

Author: Jan Wieck

src/backend/storage/buffer/buf_init.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/buffer/buf_init.c,v 1.60 2003/12/20 17:31:21 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/buffer/buf_init.c,v 1.61 2004/01/15 16:14:26 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -231,13 +231,19 @@ BufferShmemSize(void)
 	size += hash_estimate_size(SHMEM_INDEX_SIZE, sizeof(ShmemIndexEnt));
 
 	/* size of buffer descriptors */
-	size += MAXALIGN((NBuffers + 1) * sizeof(BufferDesc));
+	size += MAXALIGN(NBuffers * sizeof(BufferDesc));
+
+	/* size of the shared replacement strategy control block */
+	size += MAXALIGN(sizeof(BufferStrategyControl));
+
+	/* size of the ARC directory blocks */
+	size += MAXALIGN(NBuffers * 2 * sizeof(BufferStrategyCDB));
 
 	/* size of data pages */
 	size += NBuffers * MAXALIGN(BLCKSZ);
 
 	/* size of buffer hash table */
-	size += hash_estimate_size(NBuffers, sizeof(BufferLookupEnt));
+	size += hash_estimate_size(NBuffers * 2, sizeof(BufferLookupEnt));
 
 	return size;
 }

src/backend/storage/buffer/freelist.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.38 2003/11/29 19:51:56 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.39 2004/01/15 16:14:26 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,54 +32,13 @@
 #include "storage/proc.h"
 #include "access/xact.h"
 
-#define STRAT_LIST_UNUSED	-1
-#define STRAT_LIST_B1		0
-#define STRAT_LIST_T1		1
-#define STRAT_LIST_T2		2
-#define STRAT_LIST_B2		3
-#define STRAT_NUM_LISTS		4
-
 #ifndef MAX
 #define MAX(a,b) (((a) > (b)) ? (a) : (b))
 #endif
 #ifndef MIN
 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
 #endif
 
-/*
- * The Cache Directory Block (CDB) of the Adaptive Replacement Cache (ARC)
- */
-typedef struct bufstratcdb
-{
-	int				prev;		/* links in the queue */
-	int				next;
-	int				list;		/* current list */
-	BufferTag		buf_tag;	/* buffer key */
-	Buffer			buf_id;		/* currently assigned data buffer */
-	TransactionId	t1_xid;		/* the xid this entry went onto T1 */
-} BufferStrategyCDB;
-
-/*
- * The shared ARC control information.
- */
-typedef struct bufstratcontrol
-{
-
-	int		target_T1_size;				/* What T1 size are we aiming for */
-	int		listUnusedCDB;				/* All unused StrategyCDB */
-	int		listHead[STRAT_NUM_LISTS];	/* ARC lists B1, T1, T2 and B2 */
-	int		listTail[STRAT_NUM_LISTS];
-	int		listSize[STRAT_NUM_LISTS];
-	Buffer	listFreeBuffers;			/* List of unused buffers */
-
-	long	num_lookup;					/* Some hit statistics */
-	long	num_hit[STRAT_NUM_LISTS];
-	time_t	stat_report;
-
-	BufferStrategyCDB	cdb[1];			/* The cache directory */
-} BufferStrategyControl;
- 
-
 static BufferStrategyControl	*StrategyControl = NULL;
 static BufferStrategyCDB		*StrategyCDB = NULL;
 

src/include/storage/buf_internals.h

@@ -1,13 +1,14 @@
 /*-------------------------------------------------------------------------
  *
  * buf_internals.h
- *	  Internal definitions for buffer manager.
+ *	  Internal definitions for buffer manager and the buffer replacement
+ *    strategy.
  *
  *
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/storage/buf_internals.h,v 1.66 2003/12/14 00:34:47 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/storage/buf_internals.h,v 1.67 2004/01/15 16:14:26 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -135,6 +136,49 @@ typedef struct
 	Buffer		id;
 } BufferLookupEnt;
 
+/*
+ * Definitions for the buffer replacement strategy
+ */
+#define STRAT_LIST_UNUSED	-1
+#define STRAT_LIST_B1		0
+#define STRAT_LIST_T1		1
+#define STRAT_LIST_T2		2
+#define STRAT_LIST_B2		3
+#define STRAT_NUM_LISTS		4
+
+/*
+ * The Cache Directory Block (CDB) of the Adaptive Replacement Cache (ARC)
+ */
+typedef struct
+{
+	int				prev;		/* links in the queue */
+	int				next;
+	int				list;		/* current list */
+	BufferTag		buf_tag;	/* buffer key */
+	Buffer			buf_id;		/* currently assigned data buffer */
+	TransactionId	t1_xid;		/* the xid this entry went onto T1 */
+} BufferStrategyCDB;
+
+/*
+ * The shared ARC control information.
+ */
+typedef struct
+{
+
+	int		target_T1_size;				/* What T1 size are we aiming for */
+	int		listUnusedCDB;				/* All unused StrategyCDB */
+	int		listHead[STRAT_NUM_LISTS];	/* ARC lists B1, T1, T2 and B2 */
+	int		listTail[STRAT_NUM_LISTS];
+	int		listSize[STRAT_NUM_LISTS];
+	Buffer	listFreeBuffers;			/* List of unused buffers */
+
+	long	num_lookup;					/* Some hit statistics */
+	long	num_hit[STRAT_NUM_LISTS];
+	time_t	stat_report;
+
+	BufferStrategyCDB	cdb[1];			/* The cache directory */
+} BufferStrategyControl;
+ 
 /* counters in buf_init.c */
 extern long int ReadBufferCount;
 extern long int ReadLocalBufferCount;