Index: backend/access/transam/xlog.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/transam/xlog.c,v
retrieving revision 1.295
diff -u -3 -p -r1.295 xlog.c
--- backend/access/transam/xlog.c	25 Mar 2008 22:42:42 -0000	1.295
+++ backend/access/transam/xlog.c	16 May 2008 18:37:22 -0000
@@ -50,6 +50,7 @@
 #include "utils/builtins.h"
 #include "utils/pg_locale.h"
 #include "utils/ps_status.h"
+#include "pg_trace.h"
 
 
 /* File path names (all relative to $PGDATA) */
@@ -1258,12 +1259,14 @@ AdvanceXLInsertBuffer(bool new_segment)
 				 * Have to write buffers while holding insert lock. This is
 				 * not good, so only write as much as we absolutely must.
 				 */
+				TRACE_POSTGRESQL_WAL_BUFFER_WRITE_START();
 				WriteRqst.Write = OldPageRqstPtr;
 				WriteRqst.Flush.xlogid = 0;
 				WriteRqst.Flush.xrecoff = 0;
 				XLogWrite(WriteRqst, false, false);
 				LWLockRelease(WALWriteLock);
 				Insert->LogwrtResult = LogwrtResult;
+				TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DONE();
 			}
 		}
 	}
@@ -5665,6 +5668,8 @@ CreateCheckPoint(int flags)
 	MemSet(&CheckpointStats, 0, sizeof(CheckpointStats));
 	CheckpointStats.ckpt_start_t = GetCurrentTimestamp();
 
+	TRACE_POSTGRESQL_CHECKPOINT_START(flags);
+
 	/*
 	 * Use a critical section to force system panic if we have trouble.
 	 */
@@ -5726,6 +5731,7 @@ CreateCheckPoint(int flags)
 			LWLockRelease(WALInsertLock);
 			LWLockRelease(CheckpointLock);
 			END_CRIT_SECTION();
+			TRACE_POSTGRESQL_CHECKPOINT_DONE(UINT_MAX,0,0,0,UINT_MAX);
 			return;
 		}
 	}
@@ -5945,6 +5951,11 @@ CreateCheckPoint(int flags)
 	if (log_checkpoints)
 		LogCheckpointEnd();
 
+	TRACE_POSTGRESQL_CHECKPOINT_DONE(CheckpointStats.ckpt_bufs_written,
+				NBuffers, CheckpointStats.ckpt_segs_added,
+				CheckpointStats.ckpt_segs_removed,
+				CheckpointStats.ckpt_segs_recycled);
+
 	LWLockRelease(CheckpointLock);
 }
 
Index: backend/storage/buffer/bufmgr.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v
retrieving revision 1.228
diff -u -3 -p -r1.228 bufmgr.c
--- backend/storage/buffer/bufmgr.c	1 Jan 2008 19:45:51 -0000	1.228
+++ backend/storage/buffer/bufmgr.c	16 May 2008 18:37:22 -0000
@@ -42,6 +42,7 @@
 #include "storage/smgr.h"
 #include "utils/resowner.h"
 #include "pgstat.h"
+#include "pg_trace.h"
 
 
 /* Note: these two macros only work on shared buffers, not local ones! */
@@ -171,6 +172,7 @@ ReadBuffer_common(Relation reln, BlockNu
 	if (isExtend)
 		blockNum = smgrnblocks(reln->rd_smgr);
 
+	TRACE_POSTGRESQL_BUFFER_READ_START(blockNum, reln->rd_node.spcNode, reln->rd_node.dbNode, reln->rd_node.relNode, isLocalBuf);
 	pgstat_count_buffer_read(reln);
 
 	if (isLocalBuf)
@@ -200,12 +202,16 @@ ReadBuffer_common(Relation reln, BlockNu
 	{
 		if (!isExtend)
 		{
+			TRACE_POSTGRESQL_BUFFER_HIT();
 			/* Just need to update stats before we exit */
 			pgstat_count_buffer_hit(reln);
 
 			if (VacuumCostActive)
 				VacuumCostBalance += VacuumCostPageHit;
 
+			TRACE_POSTGRESQL_BUFFER_READ_DONE(blockNum,
+				 reln->rd_node.spcNode, reln->rd_node.dbNode,
+				 reln->rd_node.relNode, isLocalBuf, found);
 			return BufferDescriptorGetBuffer(bufHdr);
 		}
 
@@ -257,6 +263,7 @@ ReadBuffer_common(Relation reln, BlockNu
 			} while (!StartBufferIO(bufHdr, true));
 		}
 	}
+	TRACE_POSTGRESQL_BUFFER_MISS();
 
 	/*
 	 * if we have gotten to this point, we have allocated a buffer for the
@@ -324,6 +331,9 @@ ReadBuffer_common(Relation reln, BlockNu
 	if (VacuumCostActive)
 		VacuumCostBalance += VacuumCostPageMiss;
 
+	TRACE_POSTGRESQL_BUFFER_READ_DONE(blockNum, reln->rd_node.spcNode,
+		reln->rd_node.dbNode, reln->rd_node.relNode, isLocalBuf, found);
+
 	return BufferDescriptorGetBuffer(bufHdr);
 }
 
@@ -466,6 +476,11 @@ BufferAlloc(Relation reln,
 			 * happens to be trying to split the page the first one got from
 			 * StrategyGetBuffer.)
 			 */
+
+			TRACE_POSTGRESQL_DIRTY_BUFFER_WRITE_START(blockNum,
+			  reln->rd_node.spcNode, reln->rd_node.dbNode,
+			  reln->rd_node.relNode);
+
 			if (LWLockConditionalAcquire(buf->content_lock, LW_SHARED))
 			{
 				/*
@@ -488,6 +503,11 @@ BufferAlloc(Relation reln,
 				/* OK, do the I/O */
 				FlushBuffer(buf, NULL);
 				LWLockRelease(buf->content_lock);
+
+				TRACE_POSTGRESQL_DIRTY_BUFFER_WRITE_DONE(
+				  blockNum, reln->rd_node.spcNode,
+				  reln->rd_node.dbNode, reln->rd_node.relNode,
+				  (oldFlags & BM_HINT_BITS_TEST));
 			}
 			else
 			{
@@ -1734,6 +1754,10 @@ FlushBuffer(volatile BufferDesc *buf, SM
 	buf->flags &= ~BM_JUST_DIRTIED;
 	UnlockBufHdr(buf);
 
+	TRACE_POSTGRESQL_BUFFER_WRITE_START(buf->tag.blockNum,
+		 reln->smgr_rnode.spcNode, reln->smgr_rnode.dbNode,
+		 reln->smgr_rnode.relNode);
+
 	smgrwrite(reln,
 			  buf->tag.blockNum,
 			  (char *) BufHdrGetBlock(buf),
@@ -1741,6 +1765,10 @@ FlushBuffer(volatile BufferDesc *buf, SM
 
 	BufferFlushCount++;
 
+	TRACE_POSTGRESQL_BUFFER_WRITE_DONE(buf->tag.blockNum,
+		 reln->smgr_rnode.spcNode, reln->smgr_rnode.dbNode,
+		 reln->smgr_rnode.relNode, (buf->flags & BM_HINT_BITS_TEST));
+
 	/*
 	 * Mark the buffer as clean (unless BM_JUST_DIRTIED has become set) and
 	 * end the io_in_progress state.
@@ -2155,7 +2183,7 @@ SetBufferCommitInfoNeedsSave(Buffer buff
 		Assert(bufHdr->refcount > 0);
 		if (!(bufHdr->flags & BM_DIRTY) && VacuumCostActive)
 			VacuumCostBalance += VacuumCostPageDirty;
-		bufHdr->flags |= (BM_DIRTY | BM_JUST_DIRTIED);
+		bufHdr->flags |= (BM_DIRTY | BM_JUST_DIRTIED | BM_HINT_BITS_TEST);
 		UnlockBufHdr(bufHdr);
 	}
 }
@@ -2492,7 +2520,7 @@ TerminateBufferIO(volatile BufferDesc *b
 	Assert(buf->flags & BM_IO_IN_PROGRESS);
 	buf->flags &= ~(BM_IO_IN_PROGRESS | BM_IO_ERROR);
 	if (clear_dirty && !(buf->flags & BM_JUST_DIRTIED))
-		buf->flags &= ~(BM_DIRTY | BM_CHECKPOINT_NEEDED);
+		buf->flags &= ~(BM_DIRTY | BM_CHECKPOINT_NEEDED | BM_HINT_BITS_TEST);
 	buf->flags |= set_flag_bits;
 
 	UnlockBufHdr(buf);
Index: backend/storage/lmgr/deadlock.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/storage/lmgr/deadlock.c,v
retrieving revision 1.53
diff -u -3 -p -r1.53 deadlock.c
--- backend/storage/lmgr/deadlock.c	24 Mar 2008 18:22:36 -0000	1.53
+++ backend/storage/lmgr/deadlock.c	16 May 2008 18:37:23 -0000
@@ -30,6 +30,7 @@
 #include "storage/lmgr.h"
 #include "storage/proc.h"
 #include "utils/memutils.h"
+#include "pg_trace.h"
 
 
 /* One edge in the waits-for graph */
@@ -222,6 +223,8 @@ DeadLockCheck(PGPROC *proc)
 		 */
 		int			nSoftEdges;
 
+		TRACE_POSTGRESQL_DEADLOCK_FOUND();
+
 		nWaitOrders = 0;
 		if (!FindLockCycle(proc, possibleConstraints, &nSoftEdges))
 			elog(FATAL, "deadlock seems to have disappeared");
@@ -259,6 +262,8 @@ DeadLockCheck(PGPROC *proc)
 		ProcLockWakeup(GetLocksMethodTable(lock), lock);
 	}
 
+	TRACE_POSTGRESQL_DEADLOCK_NOTFOUND(nWaitOrders);
+
 	/* Return code tells caller if we had to escape a deadlock or not */
 	if (nWaitOrders > 0)
 		return DS_SOFT_DEADLOCK;
Index: backend/storage/smgr/md.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/storage/smgr/md.c,v
retrieving revision 1.136
diff -u -3 -p -r1.136 md.c
--- backend/storage/smgr/md.c	10 Mar 2008 20:06:27 -0000	1.136
+++ backend/storage/smgr/md.c	16 May 2008 18:37:23 -0000
@@ -26,6 +26,7 @@
 #include "storage/smgr.h"
 #include "utils/hsearch.h"
 #include "utils/memutils.h"
+#include "pg_trace.h"
 
 
 /* interval for calling AbsorbFsyncRequests in mdsync */
@@ -581,6 +582,8 @@ mdread(SMgrRelation reln, BlockNumber bl
 	int			nbytes;
 	MdfdVec    *v;
 
+	TRACE_POSTGRESQL_SMGR_READ_START(blocknum, reln->smgr_rnode.spcNode, reln->smgr_rnode.dbNode, reln->smgr_rnode.relNode);
+
 	v = _mdfd_getseg(reln, blocknum, false, EXTENSION_FAIL);
 
 #ifdef USE_SEGMENTED_FILES
@@ -599,7 +602,11 @@ mdread(SMgrRelation reln, BlockNumber bl
 						reln->smgr_rnode.dbNode,
 						reln->smgr_rnode.relNode)));
 
-	if ((nbytes = FileRead(v->mdfd_vfd, buffer, BLCKSZ)) != BLCKSZ)
+	nbytes = FileRead(v->mdfd_vfd, buffer, BLCKSZ);
+
+	TRACE_POSTGRESQL_SMGR_READ_DONE(blocknum, reln->smgr_rnode.spcNode, reln->smgr_rnode.dbNode, reln->smgr_rnode.relNode, nbytes, BLCKSZ);
+
+	if (nbytes != BLCKSZ)
 	{
 		if (nbytes < 0)
 			ereport(ERROR,
@@ -651,6 +658,8 @@ mdwrite(SMgrRelation reln, BlockNumber b
 	Assert(blocknum < mdnblocks(reln));
 #endif
 
+	TRACE_POSTGRESQL_SMGR_WRITE_START(blocknum, reln->smgr_rnode.spcNode, reln->smgr_rnode.dbNode, reln->smgr_rnode.relNode);
+
 	v = _mdfd_getseg(reln, blocknum, isTemp, EXTENSION_FAIL);
 
 #ifdef USE_SEGMENTED_FILES
@@ -691,6 +700,8 @@ mdwrite(SMgrRelation reln, BlockNumber b
 				 errhint("Check free disk space.")));
 	}
 
+	TRACE_POSTGRESQL_SMGR_WRITE_DONE(blocknum, reln->smgr_rnode.spcNode, reln->smgr_rnode.dbNode, reln->smgr_rnode.relNode, nbytes, BLCKSZ);
+
 	if (!isTemp)
 		register_dirty_segment(reln, v);
 }
Index: backend/tcop/postgres.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/tcop/postgres.c,v
retrieving revision 1.547
diff -u -3 -p -r1.547 postgres.c
--- backend/tcop/postgres.c	26 Mar 2008 18:48:59 -0000	1.547
+++ backend/tcop/postgres.c	16 May 2008 18:37:24 -0000
@@ -70,6 +70,7 @@
 #include "mb/pg_wchar.h"
 
 #include "pgstat.h"
+#include "pg_trace.h"
 
 extern int	optind;
 extern char *optarg;
@@ -550,6 +551,8 @@ pg_parse_query(const char *query_string)
 {
 	List	   *raw_parsetree_list;
 
+	TRACE_POSTGRESQL_QUERY_PARSE_START(query_string);
+
 	if (log_parser_stats)
 		ResetUsage();
 
@@ -659,6 +662,8 @@ pg_rewrite_query(Query *query)
 		elog_node_display(DEBUG1, "rewritten parse tree", querytree_list,
 						  Debug_pretty_print);
 
+	TRACE_POSTGRESQL_QUERY_PARSE_DONE();
+
 	return querytree_list;
 }
 
@@ -672,6 +677,8 @@ pg_plan_query(Query *querytree, int curs
 {
 	PlannedStmt *plan;
 
+	TRACE_POSTGRESQL_QUERY_PLAN_START();
+
 	/* Utility commands have no plans. */
 	if (querytree->commandType == CMD_UTILITY)
 		return NULL;
@@ -709,6 +716,7 @@ pg_plan_query(Query *querytree, int curs
 	 */
 	if (Debug_print_plan)
 		elog_node_display(DEBUG1, "plan", plan, Debug_pretty_print);
+	TRACE_POSTGRESQL_QUERY_PLAN_DONE();
 
 	return plan;
 }
@@ -796,6 +804,7 @@ exec_simple_query(const char *query_stri
 	bool		isTopLevel;
 	char		msec_str[32];
 
+
 	/*
 	 * Report query to various monitoring facilities.
 	 */
@@ -803,6 +812,8 @@ exec_simple_query(const char *query_stri
 
 	pgstat_report_activity(query_string);
 
+	TRACE_POSTGRESQL_QUERY_STATEMENT_START(MyProcPid, query_string);
+
 	/*
 	 * We use save_log_statement_stats so ShowUsage doesn't report incorrect
 	 * results because ResetUsage wasn't called.
@@ -1064,6 +1075,8 @@ exec_simple_query(const char *query_stri
 	if (save_log_statement_stats)
 		ShowUsage("QUERY STATISTICS");
 
+	TRACE_POSTGRESQL_QUERY_STATEMENT_DONE(MyProcPid, query_string);
+
 	debug_query_string = NULL;
 }
 
@@ -3484,6 +3497,7 @@ PostgresMain(int argc, char *argv[], con
 		{
 			if (IsTransactionOrTransactionBlock())
 			{
+				TRACE_POSTGRESQL_IDLE_TRANSACTION_START(GetCurrentTransactionId(), GetCurrentCommandId(false));
 				set_ps_display("idle in transaction", false);
 				pgstat_report_activity("<IDLE> in transaction");
 			}
@@ -3513,6 +3527,8 @@ PostgresMain(int argc, char *argv[], con
 		 */
 		firstchar = ReadCommand(&input_message);
 
+		TRACE_POSTGRESQL_IDLE_TRANSACTION_DONE();
+
 		/*
 		 * (4) disable async signal conditions again.
 		 */
Index: backend/tcop/pquery.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/tcop/pquery.c,v
retrieving revision 1.122
diff -u -3 -p -r1.122 pquery.c
--- backend/tcop/pquery.c	26 Mar 2008 18:48:59 -0000	1.122
+++ backend/tcop/pquery.c	16 May 2008 18:37:24 -0000
@@ -24,6 +24,7 @@
 #include "tcop/utility.h"
 #include "utils/memutils.h"
 #include "utils/snapmgr.h"
+#include "pg_trace.h"
 
 
 /*
@@ -714,6 +715,8 @@ PortalRun(Portal portal, long count, boo
 
 	AssertArg(PortalIsValid(portal));
 
+	TRACE_POSTGRESQL_QUERY_EXECUTE_START();
+
 	/* Initialize completion tag to empty string */
 	if (completionTag)
 		completionTag[0] = '\0';
@@ -864,6 +867,8 @@ PortalRun(Portal portal, long count, boo
 
 	if (log_executor_stats && portal->strategy != PORTAL_MULTI_QUERY)
 		ShowUsage("EXECUTOR STATISTICS");
+	
+	TRACE_POSTGRESQL_QUERY_EXECUTE_DONE();
 
 	return result;
 }
@@ -1234,6 +1239,8 @@ PortalRunMulti(Portal portal, bool isTop
 			 */
 			PlannedStmt *pstmt = (PlannedStmt *) stmt;
 
+			TRACE_POSTGRESQL_QUERY_EXECUTE_START();
+
 			if (log_executor_stats)
 				ResetUsage();
 
@@ -1254,6 +1261,8 @@ PortalRunMulti(Portal portal, bool isTop
 
 			if (log_executor_stats)
 				ShowUsage("EXECUTOR STATISTICS");
+
+			TRACE_POSTGRESQL_QUERY_EXECUTE_DONE();
 		}
 		else
 		{
Index: backend/utils/probes.d
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/probes.d,v
retrieving revision 1.2
diff -u -3 -p -r1.2 probes.d
--- backend/utils/probes.d	2 Jan 2008 02:42:06 -0000	1.2
+++ backend/utils/probes.d	16 May 2008 18:37:24 -0000
@@ -9,16 +9,60 @@
 
 provider postgresql {
 
-probe transaction__start(int);
-probe transaction__commit(int);
-probe transaction__abort(int);
-probe lwlock__acquire(int, int);
-probe lwlock__release(int);
-probe lwlock__startwait(int, int);
-probe lwlock__endwait(int, int);
-probe lwlock__condacquire(int, int);
-probe lwlock__condacquire__fail(int, int);
-probe lock__startwait(int, int);
-probe lock__endwait(int, int);
+	probe transaction__start(int);
+	probe transaction__commit(int);
+	probe transaction__abort(int);
+	probe lwlock__acquire(int, int);
+	probe lwlock__release(int);
+	probe lwlock__startwait(int, int);
+	probe lwlock__endwait(int, int);
+	probe lwlock__condacquire(int, int);
+	probe lwlock__condacquire__fail(int, int);
+	probe lock__startwait(int, int);
+	probe lock__endwait(int, int);
+	probe idle__transaction__start(int, int);
+	probe idle__transaction__done();
+	probe wal__buffer__write__start();
+	probe wal__buffer__write__done();
+	probe query__parse__start(char *query_string);
+	probe query__parse__done();
+	probe query__plan__start();
+	probe query__plan__done();
+	probe query__execute__start();
+	probe query__execute__done();
+	probe query__statement__start(int pid, char *query_string);
+	probe query__statement__done(int pid, char *query_string);
+	probe sort__start(int, int, int, int, int);
+	probe sort__end(int, long);
+	probe buffer__read__start(int blockNum, int tablespaceOid,
+			int databaseOid, int relationOid, int isLocalBuf);
+	probe buffer__read__done(int blockNum, int tablespaceOid,
+		 	int databaseOid, int relationOid, int isLocalBuf,
+			int isInBuffPool);
+	probe dirty__buffer__write__start(int blockNum, int tablespaceOid,
+			int databaseOid, int relationOid);
+	probe dirty__buffer__write__done(int blockNum, int tablespaceOid,
+		 	int databaseOid, int relationOid, int isHintBitsWrite);
+	probe buffer__write__start(int blockNum, int tablespaceOid,
+			int databaseOid, int relationOid);
+	probe buffer__write__done(int blockNum, int tablespaceOid,
+		 	int databaseOid, int relationOid, int isHintBitsWrite);
+	probe buffer__hit();
+	probe buffer__miss();
+	probe deadlock__found();
+	probe deadlock__notfound(int);
+	probe checkpoint__start(int checkpointFlags);
+	probe checkpoint__done(int bufsWritten, int NBuffers, int segsAdded,
+			int segsRemoved, int segsRecycled);
+	probe smgr__read__start(int blockNum, int tablespaceOid,
+			int databaseOid, int relationOid);
+	probe smgr__read__done(int blockNum, int tablespaceOid,
+	 		int databaseOid, int relationOid, int bytesRead,
+			int blockSize);
+	probe smgr__write__start(int blockNum, int tablespaceOid,
+			int databaseOid, int relationOid);
+	probe smgr__write__done(int blockNum, int tablespaceOid,
+			int databaseOid, int relationOid, int bytesRead,
+			int blockSize);
 
 };
Index: backend/utils/sort/tuplesort.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/utils/sort/tuplesort.c,v
retrieving revision 1.83
diff -u -3 -p -r1.83 tuplesort.c
--- backend/utils/sort/tuplesort.c	17 Mar 2008 03:45:36 -0000	1.83
+++ backend/utils/sort/tuplesort.c	16 May 2008 18:37:25 -0000
@@ -115,12 +115,18 @@
 #include "utils/pg_rusage.h"
 #include "utils/syscache.h"
 #include "utils/tuplesort.h"
+#include "pg_trace.h"
 
 
 /* GUC variables */
 #ifdef TRACE_SORT
 bool		trace_sort = false;
 #endif
+
+#define HEAP_SORT	0
+#define INDEX_SORT	1
+#define DATUM_SORT	2
+
 #ifdef DEBUG_BOUNDED_SORT
 bool		optimize_bounded_sort = true;
 #endif
@@ -569,6 +575,7 @@ tuplesort_begin_heap(TupleDesc tupDesc,
 			 "begin tuple sort: nkeys = %d, workMem = %d, randomAccess = %c",
 			 nkeys, workMem, randomAccess ? 't' : 'f');
 #endif
+	TRACE_POSTGRESQL_SORT_START(HEAP_SORT, false, nkeys, workMem, randomAccess);
 
 	state->nKeys = nkeys;
 
@@ -636,6 +643,8 @@ tuplesort_begin_index_btree(Relation ind
 
 	state->nKeys = RelationGetNumberOfAttributes(indexRel);
 
+	TRACE_POSTGRESQL_SORT_START(INDEX_SORT, enforceUnique, state->nKeys, workMem, randomAccess);
+
 	state->comparetup = comparetup_index_btree;
 	state->copytup = copytup_index;
 	state->writetup = writetup_index;
@@ -713,6 +722,7 @@ tuplesort_begin_datum(Oid datumType,
 			 "begin datum sort: workMem = %d, randomAccess = %c",
 			 workMem, randomAccess ? 't' : 'f');
 #endif
+	TRACE_POSTGRESQL_SORT_START(DATUM_SORT, false, 1, workMem, randomAccess);
 
 	state->nKeys = 1;			/* always a one-column sort */
 
@@ -825,6 +835,11 @@ tuplesort_end(Tuplesortstate *state)
 	}
 #endif
 
+	TRACE_POSTGRESQL_SORT_END(state->tapeset,
+			(state->tapeset ? LogicalTapeSetBlocks(true) :
+			(state->allowedMem - state->availMem + 1023) / 1024));
+
+
 	MemoryContextSwitchTo(oldcontext);
 
 	/*
Index: include/storage/buf_internals.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/storage/buf_internals.h,v
retrieving revision 1.95
diff -u -3 -p -r1.95 buf_internals.h
--- include/storage/buf_internals.h	1 Jan 2008 19:45:58 -0000	1.95
+++ include/storage/buf_internals.h	16 May 2008 18:37:27 -0000
@@ -36,6 +36,7 @@
 #define BM_JUST_DIRTIED			(1 << 5)		/* dirtied since write started */
 #define BM_PIN_COUNT_WAITER		(1 << 6)		/* have waiter for sole pin */
 #define BM_CHECKPOINT_NEEDED	(1 << 7)		/* must write for checkpoint */
+#define BM_HINT_BITS_TEST	(1 << 8)		/* test effect of writes due to hint bits */
 
 typedef bits16 BufFlags;