rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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
This commit is contained in:
Peter Eisentraut 2021-05-03 12:11:33 +02:00
parent c285babf8f
commit b94409a02f
1 changed files with 24 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/backend/storage/lmgr/lwlock.c
View File

@ -1318,7 +1318,8 @@ LWLockAcquire(LWLock *lock, LWLockMode mode)
#endif #endif
LWLockReportWaitStart(lock); 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 (;;) for (;;)
{ {
@ -1340,7 +1341,8 @@ LWLockAcquire(LWLock *lock, LWLockMode mode)
} }
#endif #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(); LWLockReportWaitEnd();
LOG_LWDEBUG("LWLockAcquire", lock, "awakened"); LOG_LWDEBUG("LWLockAcquire", lock, "awakened");
@ -1349,7 +1351,8 @@ LWLockAcquire(LWLock *lock, LWLockMode mode)
result = false; 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 */ /* Add lock to list of locks held by this backend */
held_lwlocks[num_held_lwlocks].lock = lock; held_lwlocks[num_held_lwlocks].lock = lock;
@ -1400,14 +1403,16 @@ LWLockConditionalAcquire(LWLock *lock, LWLockMode mode)
RESUME_INTERRUPTS(); RESUME_INTERRUPTS();
LOG_LWDEBUG("LWLockConditionalAcquire", lock, "failed"); 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 else
{ {
/* Add lock to list of locks held by this backend */ /* Add lock to list of locks held by this backend */
held_lwlocks[num_held_lwlocks].lock = lock; held_lwlocks[num_held_lwlocks].lock = lock;
held_lwlocks[num_held_lwlocks++].mode = mode; 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; return !mustwait;
} }
@ -1479,7 +1484,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode)
#endif #endif
LWLockReportWaitStart(lock); 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 (;;) for (;;)
{ {
@ -1497,7 +1503,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode)
Assert(nwaiters < MAX_BACKENDS); Assert(nwaiters < MAX_BACKENDS);
} }
#endif #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(); LWLockReportWaitEnd();
LOG_LWDEBUG("LWLockAcquireOrWait", lock, "awakened"); LOG_LWDEBUG("LWLockAcquireOrWait", lock, "awakened");
@ -1527,7 +1534,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode)
/* Failed to get lock, so release interrupt holdoff */ /* Failed to get lock, so release interrupt holdoff */
RESUME_INTERRUPTS(); RESUME_INTERRUPTS();
LOG_LWDEBUG("LWLockAcquireOrWait", lock, "failed"); 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 else
{ {
@ -1535,7 +1543,8 @@ LWLockAcquireOrWait(LWLock *lock, LWLockMode mode)
/* Add lock to list of locks held by this backend */ /* Add lock to list of locks held by this backend */
held_lwlocks[num_held_lwlocks].lock = lock; held_lwlocks[num_held_lwlocks].lock = lock;
held_lwlocks[num_held_lwlocks++].mode = mode; 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; return !mustwait;
@ -1695,7 +1704,8 @@ LWLockWaitForVar(LWLock *lock, uint64 *valptr, uint64 oldval, uint64 *newval)
#endif #endif
LWLockReportWaitStart(lock); 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 (;;) for (;;)
{ {
@ -1714,7 +1724,8 @@ LWLockWaitForVar(LWLock *lock, uint64 *valptr, uint64 oldval, uint64 *newval)
} }
#endif #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(); LWLockReportWaitEnd();
LOG_LWDEBUG("LWLockWaitForVar", lock, "awakened"); LOG_LWDEBUG("LWLockWaitForVar", lock, "awakened");
@ -1840,7 +1851,8 @@ LWLockRelease(LWLock *lock)
/* nobody else can have that kind of lock */ /* nobody else can have that kind of lock */
Assert(!(oldstate & LW_VAL_EXCLUSIVE)); 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 * We're still waiting for backends to get scheduled, don't wake them up