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| author | kmacy <kmacy@FreeBSD.org> | 2007-02-27 06:42:05 +0000 |
|---|---|---|
| committer | kmacy <kmacy@FreeBSD.org> | 2007-02-27 06:42:05 +0000 |
| commit | b7672bad26dbe5a50937a2e258fe957b1bc19a8d (patch) | |
| tree | c7228dd81a9d5cf5855323c889da39c667a4dd5a /sys/kern/kern_mutex.c | |
| parent | 128ac1d5958eb05b5b0c08882c80a3f90ef76d1b (diff) | |
| download | FreeBSD-src-b7672bad26dbe5a50937a2e258fe957b1bc19a8d.zip FreeBSD-src-b7672bad26dbe5a50937a2e258fe957b1bc19a8d.tar.gz | |
Further improvements to LOCK_PROFILING:
- Fix missing initialization in kern_rwlock.c causing bogus times to be collected
- Move updates to the lock hash to after the lock is released for spin mutexes,
sleep mutexes, and sx locks
- Add new kernel build option LOCK_PROFILE_FAST - only update lock profiling
statistics when an acquisition is contended. This reduces the overhead of
LOCK_PROFILING to increasing system time by 20%-25% which on
"make -j8 kernel-toolchain" on a dual woodcrest is unmeasurable in terms
of wall-clock time. Contrast this to enabling lock profiling without
LOCK_PROFILE_FAST and I see a 5x-6x slowdown in wall-clock time.
Diffstat (limited to 'sys/kern/kern_mutex.c')
| -rw-r--r-- | sys/kern/kern_mutex.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c index b3b652e..00d0353 100644 --- a/sys/kern/kern_mutex.c +++ b/sys/kern/kern_mutex.c @@ -158,6 +158,8 @@ void _mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line) { + struct lock_object lo; + MPASS(curthread != NULL); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_unlock() of destroyed mutex @ %s:%d", file, line)); @@ -169,9 +171,12 @@ _mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line) LOCK_LOG_LOCK("UNLOCK", &m->mtx_object, opts, m->mtx_recurse, file, line); mtx_assert(m, MA_OWNED); - - lock_profile_release_lock(&m->mtx_object); +#ifdef LOCK_PROFILING + memcpy(&lo, &m->mtx_object, sizeof(lo)); + m->mtx_object.lo_flags &= ~LO_CONTESTED; +#endif _rel_sleep_lock(m, curthread, opts, file, line); + lock_profile_release_lock(&lo); } void @@ -196,6 +201,8 @@ void _mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line) { + struct lock_object lo; + MPASS(curthread != NULL); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line)); @@ -206,8 +213,12 @@ _mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line) LOCK_LOG_LOCK("UNLOCK", &m->mtx_object, opts, m->mtx_recurse, file, line); mtx_assert(m, MA_OWNED); - lock_profile_release_lock(&m->mtx_object); +#ifdef LOCK_PROFILING + memcpy(&lo, &m->mtx_object, sizeof(lo)); + m->mtx_object.lo_flags &= ~LO_CONTESTED; +#endif _rel_spin_lock(m); + lock_profile_release_lock(&lo); } /* |
