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| author | Peter Eisentraut <peter@eisentraut.org> | 2021-05-03 12:11:33 +0200 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2021-05-03 12:18:27 +0200 |
| commit | b94409a02f6122d77b5154e481c0819fed6b4c95 (patch) | |
| tree | ef9754045429b159a6b9d3384ca1d25331b05415 /src | |
| parent | c285babf8f44d86b7fd1e73e9e4f94456b825bfb (diff) | |
| download | postgresql-b94409a02f6122d77b5154e481c0819fed6b4c95.tar.gz postgresql-b94409a02f6122d77b5154e481c0819fed6b4c95.zip | |
Prevent lwlock dtrace probes from unnecessary work
If dtrace is compiled in but disabled, the lwlock dtrace probes still
evaluate their arguments. Since PostgreSQL 13, T_NAME(lock) does
nontrivial work, so it should be avoided if not needed. To fix, make
these calls conditional on the *_ENABLED() macro corresponding to each
probe.
Reviewed-by: Craig Ringer <craig.ringer@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/CAGRY4nwxKUS_RvXFW-ugrZBYxPFFM5kjwKT5O+0+Stuga5b4+Q@mail.gmail.com
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/storage/lmgr/lwlock.c | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c index 975d547f34b..55b9d7970ec 100644 --- a/src/backend/storage/lmgr/lwlock.c +++ b/src/backend/storage/lmgr/lwlock.c @@ -1318,7 +1318,8 @@ LWLockAcquire(LWLock *lock, LWLockMode mode) #endif LWLockReportWaitStart(lock); - TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_WAIT_START_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), mode); for (;;) { @@ -1340,7 +1341,8 @@ LWLockAcquire(LWLock *lock, LWLockMode mode) } #endif - TRACE_POSTGRESQL_LWLOCK_WAIT_DONE(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_WAIT_DONE_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_WAIT_DONE(T_NAME(lock), mode); LWLockReportWaitEnd(); LOG_LWDEBUG("LWLockAcquire", lock, "awakened"); @@ -1349,7 +1351,8 @@ LWLockAcquire(LWLock *lock, LWLockMode mode) result = false; } - TRACE_POSTGRESQL_LWLOCK_ACQUIRE(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_ACQUIRE_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_ACQUIRE(T_NAME(lock), mode); /* Add lock to list of locks held by this backend */ held_lwlocks[num_held_lwlocks].lock = lock; @@ -1400,14 +1403,16 @@ LWLockConditionalAcquire(LWLock *lock, LWLockMode mode) RESUME_INTERRUPTS(); LOG_LWDEBUG("LWLockConditionalAcquire", lock, "failed"); - TRACE_POSTGRESQL_LWLOCK_CONDACQUIRE_FAIL(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_CONDACQUIRE_FAIL_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_CONDACQUIRE_FAIL(T_NAME(lock), mode); } else { /* Add lock to list of locks held by this backend */ held_lwlocks[num_held_lwlocks].lock = lock; held_lwlocks[num_held_lwlocks++].mode = mode; - TRACE_POSTGRESQL_LWLOCK_CONDACQUIRE(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_CONDACQUIRE_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_CONDACQUIRE(T_NAME(lock), mode); } return !mustwait; } @@ -1479,7 +1484,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode) #endif LWLockReportWaitStart(lock); - TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_WAIT_START_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), mode); for (;;) { @@ -1497,7 +1503,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode) Assert(nwaiters < MAX_BACKENDS); } #endif - TRACE_POSTGRESQL_LWLOCK_WAIT_DONE(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_WAIT_DONE_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_WAIT_DONE(T_NAME(lock), mode); LWLockReportWaitEnd(); LOG_LWDEBUG("LWLockAcquireOrWait", lock, "awakened"); @@ -1527,7 +1534,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode) /* Failed to get lock, so release interrupt holdoff */ RESUME_INTERRUPTS(); LOG_LWDEBUG("LWLockAcquireOrWait", lock, "failed"); - TRACE_POSTGRESQL_LWLOCK_ACQUIRE_OR_WAIT_FAIL(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_ACQUIRE_OR_WAIT_FAIL_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_ACQUIRE_OR_WAIT_FAIL(T_NAME(lock), mode); } else { @@ -1535,7 +1543,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode) /* Add lock to list of locks held by this backend */ held_lwlocks[num_held_lwlocks].lock = lock; held_lwlocks[num_held_lwlocks++].mode = mode; - TRACE_POSTGRESQL_LWLOCK_ACQUIRE_OR_WAIT(T_NAME(lock), mode); + if (TRACE_POSTGRESQL_LWLOCK_ACQUIRE_OR_WAIT_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_ACQUIRE_OR_WAIT(T_NAME(lock), mode); } return !mustwait; @@ -1695,7 +1704,8 @@ LWLockWaitForVar(LWLock *lock, uint64 *valptr, uint64 oldval, uint64 *newval) #endif LWLockReportWaitStart(lock); - TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), LW_EXCLUSIVE); + if (TRACE_POSTGRESQL_LWLOCK_WAIT_START_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_WAIT_START(T_NAME(lock), LW_EXCLUSIVE); for (;;) { @@ -1714,7 +1724,8 @@ LWLockWaitForVar(LWLock *lock, uint64 *valptr, uint64 oldval, uint64 *newval) } #endif - TRACE_POSTGRESQL_LWLOCK_WAIT_DONE(T_NAME(lock), LW_EXCLUSIVE); + if (TRACE_POSTGRESQL_LWLOCK_WAIT_DONE_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_WAIT_DONE(T_NAME(lock), LW_EXCLUSIVE); LWLockReportWaitEnd(); LOG_LWDEBUG("LWLockWaitForVar", lock, "awakened"); @@ -1840,7 +1851,8 @@ LWLockRelease(LWLock *lock) /* nobody else can have that kind of lock */ Assert(!(oldstate & LW_VAL_EXCLUSIVE)); - TRACE_POSTGRESQL_LWLOCK_RELEASE(T_NAME(lock)); + if (TRACE_POSTGRESQL_LWLOCK_RELEASE_ENABLED()) + TRACE_POSTGRESQL_LWLOCK_RELEASE(T_NAME(lock)); /* * We're still waiting for backends to get scheduled, don't wake them up |