Index: src/backend/storage/buffer/bufmgr.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v
retrieving revision 1.202
diff -c -r1.202 bufmgr.c
*** src/backend/storage/buffer/bufmgr.c	6 Jan 2006 00:04:20 -0000	1.202
--- src/backend/storage/buffer/bufmgr.c	2 Mar 2006 23:54:29 -0000
***************
*** 42,47 ****
--- 42,48 ----
  
  #include "lib/stringinfo.h"
  #include "miscadmin.h"
+ #include "postmaster/bgwriter.h"
  #include "storage/buf_internals.h"
  #include "storage/bufmgr.h"
  #include "storage/bufpage.h"
***************
*** 61,66 ****
--- 62,70 ----
  #define LocalBufHdrGetBlock(bufHdr) \
  	LocalBufferBlockPointers[-((bufHdr)->buf_id + 2)]
  
+ /* interval for calling AbsorbFsyncRequests in BufferSync */
+ #define WRITES_PER_ABSORB		1000
+ 
  
  /* GUC variables */
  bool		zero_damaged_pages = false;
***************
*** 892,897 ****
--- 896,902 ----
  {
  	int			buf_id;
  	int			num_to_scan;
+ 	int			absorb_counter;
  
  	/*
  	 * Find out where to start the circular scan.
***************
*** 905,913 ****
  	 * Loop over all buffers.
  	 */
  	num_to_scan = NBuffers;
  	while (num_to_scan-- > 0)
  	{
! 		(void) SyncOneBuffer(buf_id, false);
  		if (++buf_id >= NBuffers)
  			buf_id = 0;
  	}
--- 910,932 ----
  	 * Loop over all buffers.
  	 */
  	num_to_scan = NBuffers;
+ 	absorb_counter = WRITES_PER_ABSORB;
  	while (num_to_scan-- > 0)
  	{
! 		if (SyncOneBuffer(buf_id, false))
! 		{
! 			/*
! 			 * If in bgwriter, absorb pending fsync requests after each
! 			 * WRITES_PER_ABSORB write operations, to prevent overflow of
! 			 * the fsync request queue.  If not in bgwriter process, this is
! 			 * a no-op.
! 			 */
! 			if (--absorb_counter <= 0)
! 			{
! 				AbsorbFsyncRequests();
! 				absorb_counter = WRITES_PER_ABSORB;
! 			}
! 		}
  		if (++buf_id >= NBuffers)
  			buf_id = 0;
  	}
Index: src/backend/storage/smgr/md.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v
retrieving revision 1.118
diff -c -r1.118 md.c
*** src/backend/storage/smgr/md.c	15 Oct 2005 02:49:26 -0000	1.118
--- src/backend/storage/smgr/md.c	2 Mar 2006 23:54:29 -0000
***************
*** 28,33 ****
--- 28,36 ----
  #include "utils/memutils.h"
  
  
+ /* interval for calling AbsorbFsyncRequests in mdsync */
+ #define FSYNCS_PER_ABSORB		10
+ 
  /*
   *	The magnetic disk storage manager keeps track of open file
   *	descriptors in its own descriptor pool.  This is done to make it
***************
*** 702,707 ****
--- 705,711 ----
  {
  	HASH_SEQ_STATUS hstat;
  	PendingOperationEntry *entry;
+ 	int			absorb_counter;
  
  	if (!pendingOpsTable)
  		return false;
***************
*** 714,719 ****
--- 718,724 ----
  	 */
  	AbsorbFsyncRequests();
  
+ 	absorb_counter = FSYNCS_PER_ABSORB;
  	hash_seq_init(&hstat, pendingOpsTable);
  	while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL)
  	{
***************
*** 728,733 ****
--- 733,751 ----
  			MdfdVec    *seg;
  
  			/*
+ 			 * If in bgwriter, absorb pending requests every so often to
+ 			 * prevent overflow of the fsync request queue.  The hashtable
+ 			 * code does not specify whether entries added by this will be
+ 			 * visited by our search, but we don't really care: it's OK if
+ 			 * we do, and OK if we don't.
+ 			 */
+ 			if (--absorb_counter <= 0)
+ 			{
+ 				AbsorbFsyncRequests();
+ 				absorb_counter = FSYNCS_PER_ABSORB;
+ 			}
+ 
+ 			/*
  			 * Find or create an smgr hash entry for this relation. This may
  			 * seem a bit unclean -- md calling smgr?  But it's really the
  			 * best solution.  It ensures that the open file reference isn't