faster-locallock-scan.patch

diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 3bb5ce3..9475fe1 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -794,6 +794,7 @@ LockAcquireExtended(const LOCKTAG *locktag,
 	 */
 	if (!found)
 	{
+		dlist_push_head(&MyProc->localLocks, &locallock->procLink);
 		locallock->lock = NULL;
 		locallock->proclock = NULL;
 		locallock->hashcode = LockTagHashCode(&(localtag.lock));
@@ -1320,6 +1321,7 @@ RemoveLocalLock(LOCALLOCK *locallock)
 		SpinLockRelease(&FastPathStrongRelationLocks->mutex);
 	}
 
+	dlist_delete(&locallock->procLink);
 	if (!hash_search(LockMethodLocalHash,
 					 (void *) &(locallock->tag),
 					 HASH_REMOVE, NULL))
@@ -2088,7 +2090,7 @@ LockRelease(const LOCKTAG *locktag, LOCKMODE lockmode, bool sessionLock)
 void
 LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
 {
-	HASH_SEQ_STATUS status;
+	dlist_mutable_iter iter;
 	LockMethod	lockMethodTable;
 	int			i,
 				numLockModes;
@@ -2126,10 +2128,10 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
 	 * pointers.  Fast-path locks are cleaned up during the locallock table
 	 * scan, though.
 	 */
-	hash_seq_init(&status, LockMethodLocalHash);
-
-	while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+	dlist_foreach_modify(iter, &MyProc->localLocks)
 	{
+		locallock = dlist_container(LOCALLOCK, procLink, iter.cur);
+
 		/*
 		 * If the LOCALLOCK entry is unused, we must've run out of shared
 		 * memory while trying to set up this lock.  Just forget the local
@@ -2362,16 +2364,16 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
 void
 LockReleaseSession(LOCKMETHODID lockmethodid)
 {
-	HASH_SEQ_STATUS status;
+	dlist_mutable_iter iter;
 	LOCALLOCK  *locallock;
 
 	if (lockmethodid <= 0 || lockmethodid >= lengthof(LockMethods))
 		elog(ERROR, "unrecognized lock method: %d", lockmethodid);
 
-	hash_seq_init(&status, LockMethodLocalHash);
-
-	while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+	dlist_foreach_modify(iter, &MyProc->localLocks)
 	{
+		locallock = dlist_container(LOCALLOCK, procLink, iter.cur);
+
 		/* Ignore items that are not of the specified lock method */
 		if (LOCALLOCK_LOCKMETHOD(*locallock) != lockmethodid)
 			continue;
@@ -2394,13 +2396,14 @@ LockReleaseCurrentOwner(LOCALLOCK **locallocks, int nlocks)
 {
 	if (locallocks == NULL)
 	{
-		HASH_SEQ_STATUS status;
+		dlist_mutable_iter iter;
 		LOCALLOCK  *locallock;
 
-		hash_seq_init(&status, LockMethodLocalHash);
-
-		while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+		dlist_foreach_modify(iter, &MyProc->localLocks)
+		{
+			locallock = dlist_container(LOCALLOCK, procLink, iter.cur);
 			ReleaseLockIfHeld(locallock, false);
+		}
 	}
 	else
 	{
@@ -2493,13 +2496,14 @@ LockReassignCurrentOwner(LOCALLOCK **locallocks, int nlocks)
 
 	if (locallocks == NULL)
 	{
-		HASH_SEQ_STATUS status;
+		dlist_mutable_iter iter;
 		LOCALLOCK  *locallock;
 
-		hash_seq_init(&status, LockMethodLocalHash);
-
-		while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+		dlist_foreach_modify(iter, &MyProc->localLocks)
+		{
+			locallock = dlist_container(LOCALLOCK, procLink, iter.cur);
 			LockReassignOwner(locallock, parent);
+		}
 	}
 	else
 	{
@@ -3133,8 +3137,7 @@ LockRefindAndRelease(LockMethod lockMethodTable, PGPROC *proc,
 void
 AtPrepare_Locks(void)
 {
-	HASH_SEQ_STATUS status;
-	LOCALLOCK  *locallock;
+	dlist_mutable_iter iter;
 
 	/*
 	 * For the most part, we don't need to touch shared memory for this ---
@@ -3142,10 +3145,9 @@ AtPrepare_Locks(void)
 	 * Fast-path locks are an exception, however: we move any such locks to
 	 * the main table before allowing PREPARE TRANSACTION to succeed.
 	 */
-	hash_seq_init(&status, LockMethodLocalHash);
-
-	while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+	dlist_foreach_modify(iter, &MyProc->localLocks)
 	{
+		LOCALLOCK  *locallock = dlist_container(LOCALLOCK, procLink, iter.cur);
 		TwoPhaseLockRecord record;
 		LOCALLOCKOWNER *lockOwners = locallock->lockOwners;
 		bool		haveSessionLock;
@@ -3244,8 +3246,7 @@ void
 PostPrepare_Locks(TransactionId xid)
 {
 	PGPROC	   *newproc = TwoPhaseGetDummyProc(xid);
-	HASH_SEQ_STATUS status;
-	LOCALLOCK  *locallock;
+	dlist_mutable_iter iter;
 	LOCK	   *lock;
 	PROCLOCK   *proclock;
 	PROCLOCKTAG proclocktag;
@@ -3267,10 +3268,9 @@ PostPrepare_Locks(TransactionId xid)
 	 * pointing to the same proclock, and we daren't end up with any dangling
 	 * pointers.
 	 */
-	hash_seq_init(&status, LockMethodLocalHash);
-
-	while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+	dlist_foreach_modify(iter, &MyProc->localLocks)
 	{
+		LOCALLOCK  *locallock = dlist_container(LOCALLOCK, procLink, iter.cur);
 		LOCALLOCKOWNER *lockOwners = locallock->lockOwners;
 		bool		haveSessionLock;
 		bool		haveXactLock;
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 89c80fb..a22d73a 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -389,6 +389,7 @@ InitProcess(void)
 	MyProc->lwWaitMode = 0;
 	MyProc->waitLock = NULL;
 	MyProc->waitProcLock = NULL;
+	dlist_init(&MyProc->localLocks);
 #ifdef USE_ASSERT_CHECKING
 	{
 		int			i;
@@ -568,6 +569,7 @@ InitAuxiliaryProcess(void)
 	MyProc->lwWaitMode = 0;
 	MyProc->waitLock = NULL;
 	MyProc->waitProcLock = NULL;
+	dlist_init(&MyProc->localLocks);
 #ifdef USE_ASSERT_CHECKING
 	{
 		int			i;
diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
index 16b927c..20887f4 100644
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -18,6 +18,7 @@
 #error "lock.h may not be included from frontend code"
 #endif
 
+#include "lib/ilist.h"
 #include "storage/lockdefs.h"
 #include "storage/backendid.h"
 #include "storage/lwlock.h"
@@ -406,6 +407,7 @@ typedef struct LOCALLOCK
 	/* data */
 	LOCK	   *lock;			/* associated LOCK object, if any */
 	PROCLOCK   *proclock;		/* associated PROCLOCK object, if any */
+	dlist_node  procLink;		/* list link in PGPROC's list of LOCALLOCKs */
 	uint32		hashcode;		/* copy of LOCKTAG's hash value */
 	int64		nLocks;			/* total number of times lock is held */
 	bool		holdsStrongLockCount;	/* bumped FastPathStrongRelationLocks */
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index d203acb..031e004 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -138,6 +138,7 @@ struct PGPROC
 	/* waitLock and waitProcLock are NULL if not currently waiting. */
 	LOCK	   *waitLock;		/* Lock object we're sleeping on ... */
 	PROCLOCK   *waitProcLock;	/* Per-holder info for awaited lock */
+	dlist_head localLocks;		/* List of LOCALLOCKs */
 	LOCKMODE	waitLockMode;	/* type of lock we're waiting for */
 	LOCKMASK	heldLocks;		/* bitmask for lock types already held on this
 								 * lock object by this backend */