Undo LOCK_PROFILING pessimisation after r313454 and r313455
With the option used to compile the kernel both sx and rw shared ops would always go to the slow path which added avoidable overhead even when the facility is disabled. Furthermore the increased time spent doing uncontested shared lock acquire would be bogusly added to total wait time, somewhat skewing the results. Restore old behaviour of going there only when profiling is enabled. This change is a no-op for kernels without LOCK_PROFILING (which is the default).
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Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=329451
@ -645,9 +645,12 @@ __rw_rlock_int(struct rwlock *rw LOCK_FILE_LINE_ARG_DEF)
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WITNESS_CHECKORDER(&rw->lock_object, LOP_NEWORDER, file, line, NULL);
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v = RW_READ_VALUE(rw);
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if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(rw__acquire) ||
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if (__predict_false(LOCKSTAT_PROFILE_ENABLED(rw__acquire) ||
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!__rw_rlock_try(rw, td, &v, true LOCK_FILE_LINE_ARG)))
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__rw_rlock_hard(rw, td, v LOCK_FILE_LINE_ARG);
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else
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lock_profile_obtain_lock_success(&rw->lock_object, 0, 0,
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file, line);
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LOCK_LOG_LOCK("RLOCK", &rw->lock_object, 0, 0, file, line);
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WITNESS_LOCK(&rw->lock_object, 0, file, line);
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@ -839,9 +842,11 @@ _rw_runlock_cookie_int(struct rwlock *rw LOCK_FILE_LINE_ARG_DEF)
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td = curthread;
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v = RW_READ_VALUE(rw);
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if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(rw__release) ||
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if (__predict_false(LOCKSTAT_PROFILE_ENABLED(rw__release) ||
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!__rw_runlock_try(rw, td, &v)))
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__rw_runlock_hard(rw, td, v LOCK_FILE_LINE_ARG);
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else
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lock_profile_release_lock(&rw->lock_object);
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TD_LOCKS_DEC(curthread);
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}
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@ -1122,9 +1122,12 @@ _sx_slock_int(struct sx *sx, int opts LOCK_FILE_LINE_ARG_DEF)
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error = 0;
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x = SX_READ_VALUE(sx);
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if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(sx__acquire) ||
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if (__predict_false(LOCKSTAT_PROFILE_ENABLED(sx__acquire) ||
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!__sx_slock_try(sx, &x LOCK_FILE_LINE_ARG)))
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error = _sx_slock_hard(sx, opts, x LOCK_FILE_LINE_ARG);
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else
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lock_profile_obtain_lock_success(&sx->lock_object, 0, 0,
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file, line);
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if (error == 0) {
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LOCK_LOG_LOCK("SLOCK", &sx->lock_object, 0, 0, file, line);
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WITNESS_LOCK(&sx->lock_object, 0, file, line);
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@ -1252,9 +1255,11 @@ _sx_sunlock_int(struct sx *sx LOCK_FILE_LINE_ARG_DEF)
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LOCK_LOG_LOCK("SUNLOCK", &sx->lock_object, 0, 0, file, line);
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x = SX_READ_VALUE(sx);
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if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(sx__release) ||
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if (__predict_false(LOCKSTAT_PROFILE_ENABLED(sx__release) ||
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!_sx_sunlock_try(sx, &x)))
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_sx_sunlock_hard(sx, x LOCK_FILE_LINE_ARG);
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else
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lock_profile_release_lock(&sx->lock_object);
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TD_LOCKS_DEC(curthread);
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}
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@ -109,12 +109,7 @@ extern volatile int lockstat_enabled;
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LOCKSTAT_RECORD1(probe, lp, a); \
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} while (0)
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#ifndef LOCK_PROFILING
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#define LOCKSTAT_PROFILE_ENABLED(probe) __predict_false(lockstat_enabled)
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#define LOCKSTAT_OOL_PROFILE_ENABLED(probe) LOCKSTAT_PROFILE_ENABLED(probe)
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#else
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#define LOCKSTAT_OOL_PROFILE_ENABLED(probe) 1
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#endif
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struct lock_object;
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uint64_t lockstat_nsecs(struct lock_object *);
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@ -139,10 +134,7 @@ uint64_t lockstat_nsecs(struct lock_object *);
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#define LOCKSTAT_PROFILE_RELEASE_RWLOCK(probe, lp, a) \
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LOCKSTAT_PROFILE_RELEASE_LOCK(probe, lp)
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#ifndef LOCK_PROFILING
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#define LOCKSTAT_PROFILE_ENABLED(probe) 0
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#endif
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#define LOCKSTAT_OOL_PROFILE_ENABLED(probe) 1
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#endif /* !KDTRACE_HOOKS */
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