diff options
| author | John Baldwin <jhb@FreeBSD.org> | 2002-05-21 22:26:35 +0000 |
|---|---|---|
| committer | John Baldwin <jhb@FreeBSD.org> | 2002-05-21 22:26:35 +0000 |
| commit | 703fc290fbd69962f3ce0744f1f5a66a84c8fe23 (patch) | |
| tree | 99efaaa18609babbbefc08ae7aeceebab4803498 /sys | |
| parent | ec418160098a0f5ba38011095b49c1c9be7e887c (diff) | |
| download | src-703fc290fbd69962f3ce0744f1f5a66a84c8fe23.tar.gz src-703fc290fbd69962f3ce0744f1f5a66a84c8fe23.zip | |
Add appropriate IA32 "pause" instructions to improve performanec on
Pentium 4's and newer IA32 processors. The "pause" instruction has been
verified by Intel to be a NOP on all currently existing IA32 processors
prior to the Pentium 4.
Notes
Notes:
svn path=/head/; revision=97086
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/kern_mutex.c | 18 | ||||
| -rw-r--r-- | sys/kern/subr_turnstile.c | 18 |
2 files changed, 34 insertions, 2 deletions
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c index 153b5058e301..e1428b3d2186 100644 --- a/sys/kern/kern_mutex.c +++ b/sys/kern/kern_mutex.c @@ -488,6 +488,9 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line) */ if ((v = m->mtx_lock) == MTX_UNOWNED) { mtx_unlock_spin(&sched_lock); +#ifdef __i386__ + cpu_pause(); +#endif continue; } @@ -515,6 +518,9 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line) !atomic_cmpset_ptr(&m->mtx_lock, (void *)v, (void *)(v | MTX_CONTESTED))) { mtx_unlock_spin(&sched_lock); +#ifdef __i386__ + cpu_pause(); +#endif continue; } @@ -527,6 +533,9 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line) if (m != &Giant && owner->td_kse != NULL && owner->td_kse->ke_oncpu != NOCPU) { mtx_unlock_spin(&sched_lock); +#ifdef __i386__ + cpu_pause(); +#endif continue; } #endif /* SMP && ADAPTIVE_MUTEXES */ @@ -619,8 +628,12 @@ _mtx_lock_spin(struct mtx *m, int opts, const char *file, int line) /* Give interrupts a chance while we spin. */ critical_exit(); while (m->mtx_lock != MTX_UNOWNED) { - if (i++ < 10000000) + if (i++ < 10000000) { +#ifdef __i386__ + cpu_pause(); +#endif continue; + } if (i < 60000000) DELAY(1); #ifdef DDB @@ -630,6 +643,9 @@ _mtx_lock_spin(struct mtx *m, int opts, const char *file, int line) #endif panic("spin lock %s held by %p for > 5 seconds", m->mtx_object.lo_name, (void *)m->mtx_lock); +#ifdef __i386__ + cpu_pause(); +#endif } critical_enter(); } diff --git a/sys/kern/subr_turnstile.c b/sys/kern/subr_turnstile.c index 153b5058e301..e1428b3d2186 100644 --- a/sys/kern/subr_turnstile.c +++ b/sys/kern/subr_turnstile.c @@ -488,6 +488,9 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line) */ if ((v = m->mtx_lock) == MTX_UNOWNED) { mtx_unlock_spin(&sched_lock); +#ifdef __i386__ + cpu_pause(); +#endif continue; } @@ -515,6 +518,9 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line) !atomic_cmpset_ptr(&m->mtx_lock, (void *)v, (void *)(v | MTX_CONTESTED))) { mtx_unlock_spin(&sched_lock); +#ifdef __i386__ + cpu_pause(); +#endif continue; } @@ -527,6 +533,9 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line) if (m != &Giant && owner->td_kse != NULL && owner->td_kse->ke_oncpu != NOCPU) { mtx_unlock_spin(&sched_lock); +#ifdef __i386__ + cpu_pause(); +#endif continue; } #endif /* SMP && ADAPTIVE_MUTEXES */ @@ -619,8 +628,12 @@ _mtx_lock_spin(struct mtx *m, int opts, const char *file, int line) /* Give interrupts a chance while we spin. */ critical_exit(); while (m->mtx_lock != MTX_UNOWNED) { - if (i++ < 10000000) + if (i++ < 10000000) { +#ifdef __i386__ + cpu_pause(); +#endif continue; + } if (i < 60000000) DELAY(1); #ifdef DDB @@ -630,6 +643,9 @@ _mtx_lock_spin(struct mtx *m, int opts, const char *file, int line) #endif panic("spin lock %s held by %p for > 5 seconds", m->mtx_object.lo_name, (void *)m->mtx_lock); +#ifdef __i386__ + cpu_pause(); +#endif } critical_enter(); } |