From 6beb1c61e72c797c915427ae4e36d6bab9e0594c Mon Sep 17 00:00:00 2001 From: Atsushi Torikoshi Date: Fri, 22 Jan 2021 13:51:00 +0900 Subject: [PATCH v5] To examine the duration of locks, we did join on pg_locks and pg_stat_activity and used columns such as query_start or state_change. However, since they are the moment when queries have started or their state has changed, we could not get the exact lock duration in this way. --- contrib/amcheck/expected/check_btree.out | 4 ++-- doc/src/sgml/catalogs.sgml | 10 ++++++++++ src/backend/storage/ipc/standby.c | 8 ++++++-- src/backend/storage/lmgr/lock.c | 8 ++++++++ src/backend/storage/lmgr/proc.c | 4 ++++ src/backend/utils/adt/lockfuncs.c | 9 ++++++++- src/include/catalog/pg_proc.dat | 6 +++--- src/include/storage/lock.h | 2 ++ src/include/storage/proc.h | 1 + src/test/regress/expected/rules.out | 5 +++-- 10 files changed, 47 insertions(+), 10 deletions(-) diff --git a/contrib/amcheck/expected/check_btree.out b/contrib/amcheck/expected/check_btree.out index 13848b7449..5a3f1ef737 100644 --- a/contrib/amcheck/expected/check_btree.out +++ b/contrib/amcheck/expected/check_btree.out @@ -97,8 +97,8 @@ SELECT bt_index_parent_check('bttest_b_idx'); SELECT * FROM pg_locks WHERE relation = ANY(ARRAY['bttest_a', 'bttest_a_idx', 'bttest_b', 'bttest_b_idx']::regclass[]) AND pid = pg_backend_pid(); - locktype | database | relation | page | tuple | virtualxid | transactionid | classid | objid | objsubid | virtualtransaction | pid | mode | granted | fastpath -----------+----------+----------+------+-------+------------+---------------+---------+-------+----------+--------------------+-----+------+---------+---------- + locktype | database | relation | page | tuple | virtualxid | transactionid | classid | objid | objsubid | virtualtransaction | pid | mode | granted | fastpath | waitstart +----------+----------+----------+------+-------+------------+---------------+---------+-------+----------+--------------------+-----+------+---------+----------+----------- (0 rows) COMMIT; diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 43d7a1ad90..ba003ce393 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -10589,6 +10589,16 @@ SCRAM-SHA-256$<iteration count>:&l lock table + + + + waitstart timestamptz + + + Lock acquisition wait start time. NULL if + lock acquired + + diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c index 39a30c00f7..819e00e4ab 100644 --- a/src/backend/storage/ipc/standby.c +++ b/src/backend/storage/ipc/standby.c @@ -539,13 +539,17 @@ ResolveRecoveryConflictWithDatabase(Oid dbid) void ResolveRecoveryConflictWithLock(LOCKTAG locktag, bool logging_conflict) { - TimestampTz ltime; + TimestampTz ltime, now; Assert(InHotStandby); ltime = GetStandbyLimitTime(); + now = GetCurrentTimestamp(); - if (GetCurrentTimestamp() >= ltime && ltime != 0) + if (MyProc->waitStart == 0) + MyProc->waitStart = now; + + if (now >= ltime && ltime != 0) { /* * We're already behind, so clear a path as quickly as possible. diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index 20e50247ea..ffad4e94bc 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -3627,6 +3627,12 @@ GetLockStatusData(void) instance->leaderPid = proc->pid; instance->fastpath = true; + /* + * Successfully taking fast path lock means there were no + * conflicting locks. + */ + instance->waitStart = 0; + el++; } @@ -3654,6 +3660,7 @@ GetLockStatusData(void) instance->pid = proc->pid; instance->leaderPid = proc->pid; instance->fastpath = true; + instance->waitStart = 0; el++; } @@ -3706,6 +3713,7 @@ GetLockStatusData(void) instance->pid = proc->pid; instance->leaderPid = proclock->groupLeader->pid; instance->fastpath = false; + instance->waitStart = proc->waitStart; el++; } diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index c87ffc6549..725f1d367a 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -402,6 +402,7 @@ InitProcess(void) MyProc->lwWaitMode = 0; MyProc->waitLock = NULL; MyProc->waitProcLock = NULL; + MyProc->waitStart = 0; #ifdef USE_ASSERT_CHECKING { int i; @@ -1262,6 +1263,8 @@ ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable) } else enable_timeout_after(DEADLOCK_TIMEOUT, DeadlockTimeout); + + MyProc->waitStart = get_timeout_start_time(DEADLOCK_TIMEOUT); } else if (log_recovery_conflict_waits) { @@ -1678,6 +1681,7 @@ ProcWakeup(PGPROC *proc, ProcWaitStatus waitStatus) proc->waitLock = NULL; proc->waitProcLock = NULL; proc->waitStatus = waitStatus; + proc->waitStart = 0; /* And awaken it */ SetLatch(&proc->procLatch); diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c index b1cf5b79a7..97f0265c12 100644 --- a/src/backend/utils/adt/lockfuncs.c +++ b/src/backend/utils/adt/lockfuncs.c @@ -63,7 +63,7 @@ typedef struct } PG_Lock_Status; /* Number of columns in pg_locks output */ -#define NUM_LOCK_STATUS_COLUMNS 15 +#define NUM_LOCK_STATUS_COLUMNS 16 /* * VXIDGetDatum - Construct a text representation of a VXID @@ -142,6 +142,8 @@ pg_lock_status(PG_FUNCTION_ARGS) BOOLOID, -1, 0); TupleDescInitEntry(tupdesc, (AttrNumber) 15, "fastpath", BOOLOID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 16, "waitstart", + TIMESTAMPTZOID, -1, 0); funcctx->tuple_desc = BlessTupleDesc(tupdesc); @@ -336,6 +338,10 @@ pg_lock_status(PG_FUNCTION_ARGS) values[12] = CStringGetTextDatum(GetLockmodeName(instance->locktag.locktag_lockmethodid, mode)); values[13] = BoolGetDatum(granted); values[14] = BoolGetDatum(instance->fastpath); + if (!granted && instance->waitStart != 0) + values[15] = TimestampTzGetDatum(instance->waitStart); + else + nulls[15] = true; tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls); result = HeapTupleGetDatum(tuple); @@ -406,6 +412,7 @@ pg_lock_status(PG_FUNCTION_ARGS) values[12] = CStringGetTextDatum("SIReadLock"); values[13] = BoolGetDatum(true); values[14] = BoolGetDatum(false); + nulls[15] = true; tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls); result = HeapTupleGetDatum(tuple); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index b5f52d4e4a..61310781ca 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5986,9 +5986,9 @@ { oid => '1371', descr => 'view system lock information', proname => 'pg_lock_status', prorows => '1000', proretset => 't', provolatile => 'v', prorettype => 'record', proargtypes => '', - proallargtypes => '{text,oid,oid,int4,int2,text,xid,oid,oid,int2,text,int4,text,bool,bool}', - proargmodes => '{o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}', - proargnames => '{locktype,database,relation,page,tuple,virtualxid,transactionid,classid,objid,objsubid,virtualtransaction,pid,mode,granted,fastpath}', + proallargtypes => '{text,oid,oid,int4,int2,text,xid,oid,oid,int2,text,int4,text,bool,bool,timestamptz}', + proargmodes => '{o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}', + proargnames => '{locktype,database,relation,page,tuple,virtualxid,transactionid,classid,objid,objsubid,virtualtransaction,pid,mode,granted,fastpath,waitstart}', prosrc => 'pg_lock_status' }, { oid => '2561', descr => 'get array of PIDs of sessions blocking specified backend PID from acquiring a heavyweight lock', diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h index 2e6ef174e9..cf312bc55b 100644 --- a/src/include/storage/lock.h +++ b/src/include/storage/lock.h @@ -22,6 +22,7 @@ #include "storage/lockdefs.h" #include "storage/lwlock.h" #include "storage/shmem.h" +#include "utils/timestamp.h" /* struct PGPROC is declared in proc.h, but must forward-reference it */ typedef struct PGPROC PGPROC; @@ -445,6 +446,7 @@ typedef struct LockInstanceData LOCKMODE waitLockMode; /* lock awaited by this PGPROC, if any */ BackendId backend; /* backend ID of this PGPROC */ LocalTransactionId lxid; /* local transaction ID of this PGPROC */ + TimestampTz waitStart; /* time at which this PGPROC started waiting for lock */ int pid; /* pid of this PGPROC */ int leaderPid; /* pid of group leader; = pid if no group */ bool fastpath; /* taken via fastpath? */ diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 683ab64f76..83b5ec3bab 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -181,6 +181,7 @@ struct PGPROC LOCKMODE waitLockMode; /* type of lock we're waiting for */ LOCKMASK heldLocks; /* bitmask for lock types already held on this * lock object by this backend */ + TimestampTz waitStart; /* time at which wait for lock acquisition started */ bool delayChkpt; /* true if this proc delays checkpoint start */ diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 6173473de9..5b86c7d5f2 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1394,8 +1394,9 @@ pg_locks| SELECT l.locktype, l.pid, l.mode, l.granted, - l.fastpath - FROM pg_lock_status() l(locktype, database, relation, page, tuple, virtualxid, transactionid, classid, objid, objsubid, virtualtransaction, pid, mode, granted, fastpath); + l.fastpath, + l.waitstart + FROM pg_lock_status() l(locktype, database, relation, page, tuple, virtualxid, transactionid, classid, objid, objsubid, virtualtransaction, pid, mode, granted, fastpath, waitstart); pg_matviews| SELECT n.nspname AS schemaname, c.relname AS matviewname, pg_get_userbyid(c.relowner) AS matviewowner, -- 2.18.1