Refactor LWLocks and pg_stat_activity new field

Author: ildus

doc/src/sgml/monitoring.sgml

@@ -629,6 +629,11 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
      <entry><type>boolean</></entry>
      <entry>True if this backend is currently waiting on a lock</entry>
     </row>
+    <row>
+     <entry><structfield>wait_event</></entry>
+     <entry><type>text</></entry>
+     <entry>Name of a current wait event in backend</entry>
+    </row>
     <row>
      <entry><structfield>state</></entry>
      <entry><type>text</></entry>

src/backend/access/transam/clog.c

@@ -457,7 +457,8 @@ CLOGShmemInit(void)
 {
 	ClogCtl->PagePrecedes = CLOGPagePrecedes;
 	SimpleLruInit(ClogCtl, "CLOG Ctl", CLOGShmemBuffers(), CLOG_LSNS_PER_PAGE,
-				  CLogControlLock, "pg_clog");
+				  CLogControlLock, "pg_clog",
+				  "CLogBufferLocks");
 }
 
 /*

src/backend/access/transam/commit_ts.c

@@ -466,7 +466,8 @@ CommitTsShmemInit(void)
 
 	CommitTsCtl->PagePrecedes = CommitTsPagePrecedes;
 	SimpleLruInit(CommitTsCtl, "CommitTs Ctl", CommitTsShmemBuffers(), 0,
-				  CommitTsControlLock, "pg_commit_ts");
+				  CommitTsControlLock, "pg_commit_ts",
+				  "CommitTSBufferLocks");
 
 	commitTsShared = ShmemInitStruct("CommitTs shared",
 									 sizeof(CommitTimestampShared),

src/backend/access/transam/multixact.c

@@ -1842,10 +1842,12 @@ MultiXactShmemInit(void)
 
 	SimpleLruInit(MultiXactOffsetCtl,
 				  "MultiXactOffset Ctl", NUM_MXACTOFFSET_BUFFERS, 0,
-				  MultiXactOffsetControlLock, "pg_multixact/offsets");
+				  MultiXactOffsetControlLock, "pg_multixact/offsets",
+				  "MultiXactOffsetBufferLocks");
 	SimpleLruInit(MultiXactMemberCtl,
 				  "MultiXactMember Ctl", NUM_MXACTMEMBER_BUFFERS, 0,
-				  MultiXactMemberControlLock, "pg_multixact/members");
+				  MultiXactMemberControlLock, "pg_multixact/members",
+				  "MultiXactMemberBufferLocks");
 
 	/* Initialize our shared state struct */
 	MultiXactState = ShmemInitStruct("Shared MultiXact State",

src/backend/access/transam/slru.c

@@ -156,15 +156,20 @@ SimpleLruShmemSize(int nslots, int nlsns)
 	if (nlsns > 0)
 		sz += MAXALIGN(nslots * nlsns * sizeof(XLogRecPtr));	/* group_lsn[] */
 
+	/* size of lwlocks */
+	sz = add_size(sz, LWLockTrancheShmemSize(nslots));
+
 	return BUFFERALIGN(sz) + BLCKSZ * nslots;
 }
 
 void
 SimpleLruInit(SlruCtl ctl, const char *name, int nslots, int nlsns,
-			  LWLock *ctllock, const char *subdir)
+			  LWLock *ctllock, const char *subdir,
+			  const char *lwlocks_tranche)
 {
-	SlruShared	shared;
-	bool		found;
+	SlruShared    shared;
+	bool          found;
+	LWLockPadded *lwlock_array;
 
 	shared = (SlruShared) ShmemInitStruct(name,
 										  SimpleLruShmemSize(nslots, nlsns),
@@ -212,13 +217,18 @@ SimpleLruInit(SlruCtl ctl, const char *name, int nslots, int nlsns,
 		}
 
 		ptr += BUFFERALIGN(offset);
+
+		/* Create tranche and lwlocks required for slots */
+		LWLockCreateTranche(lwlocks_tranche, nslots, &lwlock_array);
+
+		/* Initialize slots */
 		for (slotno = 0; slotno < nslots; slotno++)
 		{
 			shared->page_buffer[slotno] = ptr;
 			shared->page_status[slotno] = SLRU_PAGE_EMPTY;
 			shared->page_dirty[slotno] = false;
 			shared->page_lru_count[slotno] = 0;
-			shared->buffer_locks[slotno] = LWLockAssign();
+			shared->buffer_locks[slotno] = &lwlock_array[slotno].lock;
 			ptr += BLCKSZ;
 		}
 	}

src/backend/access/transam/subtrans.c

@@ -179,7 +179,8 @@ SUBTRANSShmemInit(void)
 {
 	SubTransCtl->PagePrecedes = SubTransPagePrecedes;
 	SimpleLruInit(SubTransCtl, "SUBTRANS Ctl", NUM_SUBTRANS_BUFFERS, 0,
-				  SubtransControlLock, "pg_subtrans");
+				  SubtransControlLock, "pg_subtrans",
+				  "SubtransBufferLocks");
 	/* Override default assumption that writes should be fsync'd */
 	SubTransCtl->do_fsync = false;
 }

src/backend/access/transam/xlog.c

@@ -4679,11 +4679,12 @@ XLOGShmemInit(void)
 
 	XLogCtl->Insert.WALInsertLockTrancheId = LWLockNewTrancheId();
 
-	XLogCtl->Insert.WALInsertLockTranche.name = "WALInsertLocks";
+	strcpy(XLogCtl->Insert.WALInsertLockTranche.name, "WALInsertLocks");
 	XLogCtl->Insert.WALInsertLockTranche.array_base = WALInsertLocks;
 	XLogCtl->Insert.WALInsertLockTranche.array_stride = sizeof(WALInsertLockPadded);
 
-	LWLockRegisterTranche(XLogCtl->Insert.WALInsertLockTrancheId, &XLogCtl->Insert.WALInsertLockTranche);
+	LWLockRegisterTranche(XLogCtl->Insert.WALInsertLockTrancheId,
+		&XLogCtl->Insert.WALInsertLockTranche);
 	for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++)
 	{
 		LWLockInitialize(&WALInsertLocks[i].l.lock,

src/backend/catalog/system_views.sql

@@ -623,6 +623,7 @@ CREATE VIEW pg_stat_activity AS
             S.query_start,
             S.state_change,
             S.waiting,
+            S.wait_event,
             S.state,
             S.backend_xid,
             s.backend_xmin,

src/backend/commands/async.c

@@ -469,7 +469,7 @@ AsyncShmemInit(void)
 	 */
 	AsyncCtl->PagePrecedes = asyncQueuePagePrecedes;
 	SimpleLruInit(AsyncCtl, "Async Ctl", NUM_ASYNC_BUFFERS, 0,
-				  AsyncCtlLock, "pg_notify");
+				  AsyncCtlLock, "pg_notify", "AsyncBufferLocks");
 	/* Override default assumption that writes should be fsync'd */
 	AsyncCtl->do_fsync = false;
 

src/backend/libpq/be-secure.c

@@ -36,6 +36,7 @@
 #include "tcop/tcopprot.h"
 #include "utils/memutils.h"
 #include "storage/proc.h"
+#include "pgstat.h"
 
 
 char	   *ssl_cert_file;
@@ -122,6 +123,8 @@ secure_read(Port *port, void *ptr, size_t len)
 	ssize_t		n;
 	int			waitfor;
 
+	pgstat_report_wait_start(WAIT_NETWORK, WAIT_NETWORK_READ);
+
 retry:
 #ifdef USE_SSL
 	waitfor = 0;
@@ -168,6 +171,7 @@ secure_read(Port *port, void *ptr, size_t len)
 	 * interrupts from being processed.
 	 */
 	ProcessClientReadInterrupt(false);
+	pgstat_report_wait_end();
 
 	return n;
 }
@@ -202,6 +206,8 @@ secure_write(Port *port, void *ptr, size_t len)
 	ssize_t		n;
 	int			waitfor;
 
+	pgstat_report_wait_start(WAIT_NETWORK, WAIT_NETWORK_WRITE);
+
 retry:
 	waitfor = 0;
 #ifdef USE_SSL
@@ -247,6 +253,7 @@ secure_write(Port *port, void *ptr, size_t len)
 	 * interrupts from being processed.
 	 */
 	ProcessClientWriteInterrupt(false);
+	pgstat_report_wait_end();
 
 	return n;
 }