diff options
Diffstat (limited to 'sys/kern/kern_sx.c')
| -rw-r--r-- | sys/kern/kern_sx.c | 78 |
1 files changed, 57 insertions, 21 deletions
diff --git a/sys/kern/kern_sx.c b/sys/kern/kern_sx.c index 3ba482b..5d418c2 100644 --- a/sys/kern/kern_sx.c +++ b/sys/kern/kern_sx.c @@ -47,6 +47,7 @@ __FBSDID("$FreeBSD$"); #include <sys/param.h> #include <sys/systm.h> #include <sys/kdb.h> +#include <sys/kernel.h> #include <sys/ktr.h> #include <sys/lock.h> #include <sys/mutex.h> @@ -54,6 +55,7 @@ __FBSDID("$FreeBSD$"); #include <sys/sched.h> #include <sys/sleepqueue.h> #include <sys/sx.h> +#include <sys/smp.h> #include <sys/sysctl.h> #if defined(SMP) && !defined(NO_ADAPTIVE_SX) @@ -147,6 +149,33 @@ static u_int asx_loops = 10000; static SYSCTL_NODE(_debug, OID_AUTO, sx, CTLFLAG_RD, NULL, "sxlock debugging"); SYSCTL_UINT(_debug_sx, OID_AUTO, retries, CTLFLAG_RW, &asx_retries, 0, ""); SYSCTL_UINT(_debug_sx, OID_AUTO, loops, CTLFLAG_RW, &asx_loops, 0, ""); + +static struct lock_delay_config sx_delay = { + .initial = 1000, + .step = 500, + .min = 100, + .max = 5000, +}; + +SYSCTL_INT(_debug_sx, OID_AUTO, delay_initial, CTLFLAG_RW, &sx_delay.initial, + 0, ""); +SYSCTL_INT(_debug_sx, OID_AUTO, delay_step, CTLFLAG_RW, &sx_delay.step, + 0, ""); +SYSCTL_INT(_debug_sx, OID_AUTO, delay_min, CTLFLAG_RW, &sx_delay.min, + 0, ""); +SYSCTL_INT(_debug_sx, OID_AUTO, delay_max, CTLFLAG_RW, &sx_delay.max, + 0, ""); + +static void +sx_delay_sysinit(void *dummy) +{ + + sx_delay.initial = mp_ncpus * 25; + sx_delay.step = (mp_ncpus * 25) / 2; + sx_delay.min = mp_ncpus * 5; + sx_delay.max = mp_ncpus * 25 * 10; +} +LOCK_DELAY_SYSINIT(sx_delay_sysinit); #endif void @@ -516,10 +545,12 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file, int contested = 0; #endif int error = 0; +#if defined(ADAPTIVE_SX) || defined(KDTRACE_HOOKS) + struct lock_delay_arg lda; +#endif #ifdef KDTRACE_HOOKS uintptr_t state; - 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 @@ -527,6 +558,12 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file, if (SCHEDULER_STOPPED()) return (0); +#if defined(ADAPTIVE_SX) + lock_delay_arg_init(&lda, &sx_delay); +#elif defined(KDTRACE_HOOKS) + lock_delay_arg_init(&lda, NULL); +#endif + /* If we already hold an exclusive lock, then recurse. */ if (sx_xlocked(sx)) { KASSERT((sx->lock_object.lo_flags & LO_RECURSABLE) != 0, @@ -552,7 +589,7 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file, atomic_cmpset_acq_ptr(&sx->sx_lock, SX_LOCK_UNLOCKED, tid)) break; #ifdef KDTRACE_HOOKS - spin_cnt++; + lda.spin_cnt++; #endif #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); @@ -581,12 +618,8 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file, sx->lock_object.lo_name); GIANT_SAVE(); while (SX_OWNER(sx->sx_lock) == x && - 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(curthread), "running"); continue; @@ -608,7 +641,7 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file, break; cpu_spinwait(); #ifdef KDTRACE_HOOKS - spin_cnt++; + lda.spin_cnt++; #endif } KTR_STATE0(KTR_SCHED, "thread", @@ -728,7 +761,7 @@ _sx_xlock_hard(struct sx *sx, uintptr_t tid, int opts, const char *file, LOCKSTAT_RECORD4(LS_SX_XLOCK_BLOCK, sx, sleep_time, LOCKSTAT_WRITER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); - if (spin_cnt > sleep_cnt) + if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD4(LS_SX_XLOCK_SPIN, sx, all_time - sleep_time, LOCKSTAT_WRITER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); @@ -821,10 +854,12 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line) #endif uintptr_t x; int error = 0; +#if defined(ADAPTIVE_SX) || defined(KDTRACE_HOOKS) + struct lock_delay_arg lda; +#endif #ifdef KDTRACE_HOOKS uintptr_t state; - 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 @@ -832,6 +867,11 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line) if (SCHEDULER_STOPPED()) return (0); +#if defined(ADAPTIVE_SX) + lock_delay_arg_init(&lda, &sx_delay); +#elif defined(KDTRACE_HOOKS) + lock_delay_arg_init(&lda, NULL); +#endif #ifdef KDTRACE_HOOKS state = sx->sx_lock; all_time -= lockstat_nsecs(&sx->lock_object); @@ -843,7 +883,7 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line) */ for (;;) { #ifdef KDTRACE_HOOKS - spin_cnt++; + lda.spin_cnt++; #endif x = sx->sx_lock; @@ -891,12 +931,8 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line) "lockname:\"%s\"", sx->lock_object.lo_name); GIANT_SAVE(); while (SX_OWNER(sx->sx_lock) == x && - TD_IS_RUNNING(owner)) { -#ifdef KDTRACE_HOOKS - spin_cnt++; -#endif - cpu_spinwait(); - } + TD_IS_RUNNING(owner)) + lock_delay(&lda); KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); continue; @@ -992,7 +1028,7 @@ _sx_slock_hard(struct sx *sx, int opts, const char *file, int line) LOCKSTAT_RECORD4(LS_SX_SLOCK_BLOCK, sx, sleep_time, LOCKSTAT_READER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); - if (spin_cnt > sleep_cnt) + if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD4(LS_SX_SLOCK_SPIN, sx, all_time - sleep_time, LOCKSTAT_READER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); |
