diff options
Diffstat (limited to 'sys/kern/kern_mutex.c')
| -rw-r--r-- | sys/kern/kern_mutex.c | 68 |
1 files changed, 54 insertions, 14 deletions
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c index 8d19f2e..27038e1 100644 --- a/sys/kern/kern_mutex.c +++ b/sys/kern/kern_mutex.c @@ -57,6 +57,7 @@ __FBSDID("$FreeBSD$"); #include <sys/resourcevar.h> #include <sys/sched.h> #include <sys/sbuf.h> +#include <sys/smp.h> #include <sys/sysctl.h> #include <sys/turnstile.h> #include <sys/vmmeter.h> @@ -140,6 +141,37 @@ struct lock_class lock_class_mtx_spin = { #endif }; +#ifdef ADAPTIVE_MUTEXES +static SYSCTL_NODE(_debug, OID_AUTO, mtx, CTLFLAG_RD, NULL, "mtx debugging"); + +static struct lock_delay_config mtx_delay = { + .initial = 1000, + .step = 500, + .min = 100, + .max = 5000, +}; + +SYSCTL_INT(_debug_mtx, OID_AUTO, delay_initial, CTLFLAG_RW, &mtx_delay.initial, + 0, ""); +SYSCTL_INT(_debug_mtx, OID_AUTO, delay_step, CTLFLAG_RW, &mtx_delay.step, + 0, ""); +SYSCTL_INT(_debug_mtx, OID_AUTO, delay_min, CTLFLAG_RW, &mtx_delay.min, + 0, ""); +SYSCTL_INT(_debug_mtx, OID_AUTO, delay_max, CTLFLAG_RW, &mtx_delay.max, + 0, ""); + +static void +mtx_delay_sysinit(void *dummy) +{ + + mtx_delay.initial = mp_ncpus * 25; + mtx_delay.step = (mp_ncpus * 25) / 2; + mtx_delay.min = mp_ncpus * 5; + mtx_delay.max = mp_ncpus * 25 * 10; +} +LOCK_DELAY_SYSINIT(mtx_delay_sysinit); +#endif + /* * System-wide mutexes */ @@ -412,9 +444,11 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts, int contested = 0; uint64_t waittime = 0; #endif +#if defined(ADAPTIVE_MUTEXES) || defined(KDTRACE_HOOKS) + struct lock_delay_arg lda; +#endif #ifdef KDTRACE_HOOKS - uint64_t spin_cnt = 0; - uint64_t sleep_cnt = 0; + u_int sleep_cnt = 0; int64_t sleep_time = 0; int64_t all_time = 0; #endif @@ -422,6 +456,11 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts, if (SCHEDULER_STOPPED()) return; +#if defined(ADAPTIVE_MUTEXES) + lock_delay_arg_init(&lda, &mtx_delay); +#elif defined(KDTRACE_HOOKS) + lock_delay_arg_init(&lda, NULL); +#endif m = mtxlock2mtx(c); if (mtx_owned(m)) { @@ -451,9 +490,11 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts, all_time -= lockstat_nsecs(&m->lock_object); #endif - while (!_mtx_obtain_lock(m, tid)) { + for (;;) { + if (m->mtx_lock == MTX_UNOWNED && _mtx_obtain_lock(m, tid)) + break; #ifdef KDTRACE_HOOKS - spin_cnt++; + lda.spin_cnt++; #endif #ifdef ADAPTIVE_MUTEXES /* @@ -473,12 +514,8 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts, "spinning", "lockname:\"%s\"", m->lock_object.lo_name); while (mtx_owner(m) == owner && - TD_IS_RUNNING(owner)) { - cpu_spinwait(); -#ifdef KDTRACE_HOOKS - spin_cnt++; -#endif - } + TD_IS_RUNNING(owner)) + lock_delay(&lda); KTR_STATE0(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "running"); @@ -572,7 +609,7 @@ __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t tid, int opts, /* * Only record the loops spinning and not sleeping. */ - if (spin_cnt > sleep_cnt) + if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD1(LS_MTX_LOCK_SPIN, m, (all_time - sleep_time)); #endif } @@ -634,8 +671,9 @@ _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t tid, int opts, #ifdef KDTRACE_HOOKS spin_time -= lockstat_nsecs(&m->lock_object); #endif - while (!_mtx_obtain_lock(m, tid)) { - + for (;;) { + if (m->mtx_lock == MTX_UNOWNED && _mtx_obtain_lock(m, tid)) + break; /* Give interrupts a chance while we spin. */ spinlock_exit(); while (m->mtx_lock != MTX_UNOWNED) { @@ -714,7 +752,9 @@ retry: m->lock_object.lo_name, file, line)); WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); - while (!_mtx_obtain_lock(m, tid)) { + for (;;) { + if (m->mtx_lock == MTX_UNOWNED && _mtx_obtain_lock(m, tid)) + break; if (m->mtx_lock == tid) { m->mtx_recurse++; break; |
