void smp_rendezvous_cpus(cpuset_t map, void (*setup_func)(void *), void (*action_func)(void *), void (*teardown_func)(void *), void *arg) { /* * In the !SMP case we just need to ensure the same initial conditions * as the SMP case. */ spinlock_enter(); if (setup_func != NULL) setup_func(arg); if (action_func != NULL) action_func(arg); if (teardown_func != NULL) teardown_func(arg); spinlock_exit(); }
static void i8259_init(struct atpic *pic, int slave) { int imr_addr; /* Reset the PIC and program with next four bytes. */ spinlock_enter(); outb(pic->at_ioaddr, ICW1_RESET | ICW1_IC4); imr_addr = pic->at_ioaddr + ICU_IMR_OFFSET; /* Start vector. */ outb(imr_addr, pic->at_intbase); /* * Setup slave links. For the master pic, indicate what line * the slave is configured on. For the slave indicate * which line on the master we are connected to. */ if (slave) outb(imr_addr, ICU_SLAVEID); else outb(imr_addr, IRQ_MASK(ICU_SLAVEID)); /* Set mode. */ if (slave) outb(imr_addr, SLAVE_MODE); else outb(imr_addr, MASTER_MODE); /* Set interrupt enable mask. */ outb(imr_addr, pic->at_imen); /* Reset is finished, default to IRR on read. */ outb(pic->at_ioaddr, OCW3_SEL | OCW3_RR); /* OCW2_L1 sets priority order to 3-7, 0-2 (com2 first). */ if (!slave) outb(pic->at_ioaddr, OCW2_R | OCW2_SL | OCW2_L1); spinlock_exit(); }
void __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; #ifdef SMP uintptr_t tid, v; #endif m = mtxlock2mtx(c); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_lock_spin() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("mtx_lock_spin() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); if (mtx_owned(m)) KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || (opts & MTX_RECURSE) != 0, ("mtx_lock_spin: recursed on non-recursive mutex %s @ %s:%d\n", m->lock_object.lo_name, file, line)); opts &= ~MTX_RECURSE; WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); #ifdef SMP spinlock_enter(); tid = (uintptr_t)curthread; v = MTX_UNOWNED; if (!_mtx_obtain_lock_fetch(m, &v, tid)) _mtx_lock_spin(m, v, opts, file, line); else LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, 0, 0, file, line); #else __mtx_lock_spin(m, curthread, opts, file, line); #endif LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); }
/* * _mtx_lock_spin: the tougher part of acquiring an MTX_SPIN lock. * * This is only called if we need to actually spin for the lock. Recursion * is handled inline. */ void _mtx_lock_spin(struct mtx *m, uintptr_t tid, int opts, const char *file, int line) { int i = 0; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m); lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); while (!_obtain_lock(m, tid)) { /* Give interrupts a chance while we spin. */ spinlock_exit(); while (m->mtx_lock != MTX_UNOWNED) { if (i++ < 10000000) { cpu_spinwait(); continue; } if (i < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); } spinlock_enter(); } if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m); LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(LS_MTX_SPIN_LOCK_ACQUIRE, m, contested, waittime, (file), (line)); LOCKSTAT_RECORD1(LS_MTX_SPIN_LOCK_SPIN, m, i); }
void cpu_reset(void) { bus_space_handle_t pmc; uint32_t reg; printf("Resetting...\n"); bus_space_map(fdtbus_bs_tag, PMC_PHYSBASE, PMC_SIZE, 0, &pmc); reg = bus_space_read_4(fdtbus_bs_tag, pmc, PMC_SCRATCH0); reg &= PMC_SCRATCH0_MODE_MASK; bus_space_write_4(fdtbus_bs_tag, pmc, PMC_SCRATCH0, reg | PMC_SCRATCH0_MODE_BOOTLOADER); /* boot to bootloader */ bus_space_read_4(fdtbus_bs_tag, pmc, PMC_SCRATCH0); reg = bus_space_read_4(fdtbus_bs_tag, pmc, PMC_CONTROL_REG); spinlock_enter(); dsb(); bus_space_write_4(fdtbus_bs_tag, pmc, PMC_CONTROL_REG, reg | 0x10); bus_space_read_4(fdtbus_bs_tag, pmc, PMC_CONTROL_REG); while(1) ; }
/* * This function is called when a thread is about to be put on run queue * because it has been made runnable or its priority has been adjusted. It * determines if the new thread should be immediately preempted to. If so, * it switches to it and eventually returns true. If not, it returns false * so that the caller may place the thread on an appropriate run queue. */ int maybe_preempt(struct thread *td) { #ifdef PREEMPTION struct thread *ctd; int cpri, pri; /* * The new thread should not preempt the current thread if any of the * following conditions are true: * * - The kernel is in the throes of crashing (panicstr). * - The current thread has a higher (numerically lower) or * equivalent priority. Note that this prevents curthread from * trying to preempt to itself. * - It is too early in the boot for context switches (cold is set). * - The current thread has an inhibitor set or is in the process of * exiting. In this case, the current thread is about to switch * out anyways, so there's no point in preempting. If we did, * the current thread would not be properly resumed as well, so * just avoid that whole landmine. * - If the new thread's priority is not a realtime priority and * the current thread's priority is not an idle priority and * FULL_PREEMPTION is disabled. * * If all of these conditions are false, but the current thread is in * a nested critical section, then we have to defer the preemption * until we exit the critical section. Otherwise, switch immediately * to the new thread. */ ctd = curthread; THREAD_LOCK_ASSERT(td, MA_OWNED); KASSERT((td->td_inhibitors == 0), ("maybe_preempt: trying to run inhibited thread")); pri = td->td_priority; cpri = ctd->td_priority; if (panicstr != NULL || pri >= cpri || cold /* || dumping */ || TD_IS_INHIBITED(ctd)) return (0); #ifndef FULL_PREEMPTION if (pri > PRI_MAX_ITHD && cpri < PRI_MIN_IDLE) return (0); #endif if (ctd->td_critnest > 1) { CTR1(KTR_PROC, "maybe_preempt: in critical section %d", ctd->td_critnest); ctd->td_owepreempt = 1; return (0); } /* * Thread is runnable but not yet put on system run queue. */ MPASS(ctd->td_lock == td->td_lock); MPASS(TD_ON_RUNQ(td)); TD_SET_RUNNING(td); CTR3(KTR_PROC, "preempting to thread %p (pid %d, %s)\n", td, td->td_proc->p_pid, td->td_name); mi_switch(SW_INVOL | SW_PREEMPT | SWT_PREEMPT, td); /* * td's lock pointer may have changed. We have to return with it * locked. */ spinlock_enter(); thread_unlock(ctd); thread_lock(td); spinlock_exit(); return (1); #else return (0); #endif }
void _thread_lock_flags(struct thread *td, int opts, const char *file, int line) { struct mtx *m; uintptr_t tid; int i; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS uint64_t spin_cnt = 0; #endif i = 0; tid = (uintptr_t)curthread; for (;;) { retry: spinlock_enter(); m = td->td_lock; KASSERT(m->mtx_lock != MTX_DESTROYED, ("thread_lock() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("thread_lock() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); if (mtx_owned(m)) KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0, ("thread_lock: recursed on non-recursive mutex %s @ %s:%d\n", m->lock_object.lo_name, file, line)); WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); while (!_obtain_lock(m, tid)) { #ifdef KDTRACE_HOOKS spin_cnt++; #endif if (m->mtx_lock == tid) { m->mtx_recurse++; break; } lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); /* Give interrupts a chance while we spin. */ spinlock_exit(); while (m->mtx_lock != MTX_UNOWNED) { if (i++ < 10000000) cpu_spinwait(); else if (i < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); if (m != td->td_lock) goto retry; } spinlock_enter(); } if (m == td->td_lock) break; _rel_spin_lock(m); /* does spinlock_exit() */ #ifdef KDTRACE_HOOKS spin_cnt++; #endif } if (m->mtx_recurse == 0) LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(LS_MTX_SPIN_LOCK_ACQUIRE, m, contested, waittime, (file), (line)); LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); LOCKSTAT_RECORD1(LS_THREAD_LOCK_SPIN, m, spin_cnt); }
void smp_rendezvous_cpus(cpuset_t map, void (* setup_func)(void *), void (* action_func)(void *), void (* teardown_func)(void *), void *arg) { int curcpumap, i, ncpus = 0; /* Look comments in the !SMP case. */ if (!smp_started) { spinlock_enter(); if (setup_func != NULL) setup_func(arg); if (action_func != NULL) action_func(arg); if (teardown_func != NULL) teardown_func(arg); spinlock_exit(); return; } CPU_FOREACH(i) { if (CPU_ISSET(i, &map)) ncpus++; } if (ncpus == 0) panic("ncpus is 0 with non-zero map"); mtx_lock_spin(&smp_ipi_mtx); /* Pass rendezvous parameters via global variables. */ smp_rv_ncpus = ncpus; smp_rv_setup_func = setup_func; smp_rv_action_func = action_func; smp_rv_teardown_func = teardown_func; smp_rv_func_arg = arg; smp_rv_waiters[1] = 0; smp_rv_waiters[2] = 0; smp_rv_waiters[3] = 0; atomic_store_rel_int(&smp_rv_waiters[0], 0); /* * Signal other processors, which will enter the IPI with * interrupts off. */ curcpumap = CPU_ISSET(curcpu, &map); CPU_CLR(curcpu, &map); ipi_selected(map, IPI_RENDEZVOUS); /* Check if the current CPU is in the map */ if (curcpumap != 0) smp_rendezvous_action(); /* * Ensure that the master CPU waits for all the other * CPUs to finish the rendezvous, so that smp_rv_* * pseudo-structure and the arg are guaranteed to not * be in use. */ while (atomic_load_acq_int(&smp_rv_waiters[3]) < ncpus) cpu_spinwait(); mtx_unlock_spin(&smp_ipi_mtx); }
static int atpic_config_intr(struct intsrc *isrc, enum intr_trigger trig, enum intr_polarity pol) { struct atpic_intsrc *ai = (struct atpic_intsrc *)isrc; u_int vector; /* Map conforming values to edge/hi and sanity check the values. */ if (trig == INTR_TRIGGER_CONFORM) trig = INTR_TRIGGER_EDGE; if (pol == INTR_POLARITY_CONFORM) pol = INTR_POLARITY_HIGH; vector = atpic_vector(isrc); if ((trig == INTR_TRIGGER_EDGE && pol == INTR_POLARITY_LOW) || (trig == INTR_TRIGGER_LEVEL && pol == INTR_POLARITY_HIGH)) { printf( "atpic: Mismatched config for IRQ%u: trigger %s, polarity %s\n", vector, trig == INTR_TRIGGER_EDGE ? "edge" : "level", pol == INTR_POLARITY_HIGH ? "high" : "low"); return (EINVAL); } /* If there is no change, just return. */ if (ai->at_trigger == trig) return (0); #ifdef PC98 if ((vector == 0 || vector == 1 || vector == 7 || vector == 8) && trig == INTR_TRIGGER_LEVEL) { if (bootverbose) printf( "atpic: Ignoring invalid level/low configuration for IRQ%u\n", vector); return (EINVAL); } return (ENXIO); #else /* * Certain IRQs can never be level/lo, so don't try to set them * that way if asked. At least some ELCR registers ignore setting * these bits as well. */ if ((vector == 0 || vector == 1 || vector == 2 || vector == 13) && trig == INTR_TRIGGER_LEVEL) { if (bootverbose) printf( "atpic: Ignoring invalid level/low configuration for IRQ%u\n", vector); return (EINVAL); } if (!elcr_found) { if (bootverbose) printf("atpic: No ELCR to configure IRQ%u as %s\n", vector, trig == INTR_TRIGGER_EDGE ? "edge/high" : "level/low"); return (ENXIO); } if (bootverbose) printf("atpic: Programming IRQ%u as %s\n", vector, trig == INTR_TRIGGER_EDGE ? "edge/high" : "level/low"); spinlock_enter(); elcr_write_trigger(atpic_vector(isrc), trig); ai->at_trigger = trig; spinlock_exit(); return (0); #endif /* PC98 */ }
void vpanic(const char *fmt, va_list ap) { #ifdef SMP cpuset_t other_cpus; #endif struct thread *td = curthread; int bootopt, newpanic; static char buf[256]; spinlock_enter(); #ifdef SMP /* * stop_cpus_hard(other_cpus) should prevent multiple CPUs from * concurrently entering panic. Only the winner will proceed * further. */ if (panicstr == NULL && !kdb_active) { other_cpus = all_cpus; CPU_CLR(PCPU_GET(cpuid), &other_cpus); stop_cpus_hard(other_cpus); } /* * Ensure that the scheduler is stopped while panicking, even if panic * has been entered from kdb. */ td->td_stopsched = 1; #endif bootopt = RB_AUTOBOOT; newpanic = 0; if (panicstr) bootopt |= RB_NOSYNC; else { bootopt |= RB_DUMP; panicstr = fmt; newpanic = 1; } if (newpanic) { (void)vsnprintf(buf, sizeof(buf), fmt, ap); panicstr = buf; cngrab(); printf("panic: %s\n", buf); } else { printf("panic: "); vprintf(fmt, ap); printf("\n"); } #ifdef SMP printf("cpuid = %d\n", PCPU_GET(cpuid)); #endif #ifdef KDB if (newpanic && trace_on_panic) kdb_backtrace(); if (debugger_on_panic) kdb_enter(KDB_WHY_PANIC, "panic"); #endif /*thread_lock(td); */ td->td_flags |= TDF_INPANIC; /* thread_unlock(td); */ if (!sync_on_panic) bootopt |= RB_NOSYNC; kern_reboot(bootopt); }
void thread_lock_flags_(struct thread *td, int opts, const char *file, int line) { struct mtx *m; uintptr_t tid; struct lock_delay_arg lda; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS int64_t spin_time = 0; #endif tid = (uintptr_t)curthread; if (SCHEDULER_STOPPED()) { /* * Ensure that spinlock sections are balanced even when the * scheduler is stopped, since we may otherwise inadvertently * re-enable interrupts while dumping core. */ spinlock_enter(); return; } lock_delay_arg_init(&lda, &mtx_spin_delay); #ifdef KDTRACE_HOOKS spin_time -= lockstat_nsecs(&td->td_lock->lock_object); #endif for (;;) { retry: spinlock_enter(); m = td->td_lock; KASSERT(m->mtx_lock != MTX_DESTROYED, ("thread_lock() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("thread_lock() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); if (mtx_owned(m)) KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0, ("thread_lock: recursed on non-recursive mutex %s @ %s:%d\n", m->lock_object.lo_name, file, line)); WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); for (;;) { if (m->mtx_lock == MTX_UNOWNED && _mtx_obtain_lock(m, tid)) break; if (m->mtx_lock == tid) { m->mtx_recurse++; break; } #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); /* Give interrupts a chance while we spin. */ spinlock_exit(); while (m->mtx_lock != MTX_UNOWNED) { if (lda.spin_cnt < 10000000) { lock_delay(&lda); } else { lda.spin_cnt++; if (lda.spin_cnt < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); } if (m != td->td_lock) goto retry; } spinlock_enter(); } if (m == td->td_lock) break; __mtx_unlock_spin(m); /* does spinlock_exit() */ } #ifdef KDTRACE_HOOKS spin_time += lockstat_nsecs(&m->lock_object); #endif if (m->mtx_recurse == 0) LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, contested, waittime, file, line); LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); #ifdef KDTRACE_HOOKS if (spin_time != 0) LOCKSTAT_RECORD1(thread__spin, m, spin_time); #endif }
/* * _mtx_lock_spin_cookie: the tougher part of acquiring an MTX_SPIN lock. * * This is only called if we need to actually spin for the lock. Recursion * is handled inline. */ void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t tid, int opts, const char *file, int line) { struct mtx *m; struct lock_delay_arg lda; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS int64_t spin_time = 0; #endif if (SCHEDULER_STOPPED()) return; lock_delay_arg_init(&lda, &mtx_spin_delay); m = mtxlock2mtx(c); if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m); KTR_STATE1(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "spinning", "lockname:\"%s\"", m->lock_object.lo_name); #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); #ifdef KDTRACE_HOOKS spin_time -= lockstat_nsecs(&m->lock_object); #endif 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) { if (lda.spin_cnt < 10000000) { lock_delay(&lda); continue; } lda.spin_cnt++; if (lda.spin_cnt < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); } spinlock_enter(); } #ifdef KDTRACE_HOOKS spin_time += lockstat_nsecs(&m->lock_object); #endif if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m); KTR_STATE0(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "running"); #ifdef KDTRACE_HOOKS LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, contested, waittime, file, line); if (spin_time != 0) LOCKSTAT_RECORD1(spin__spin, m, spin_time); #endif }
void thread_lock_flags_(struct thread *td, int opts, const char *file, int line) { struct mtx *m; uintptr_t tid, v; struct lock_delay_arg lda; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS int64_t spin_time = 0; #endif #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) int doing_lockprof = 1; #endif tid = (uintptr_t)curthread; if (SCHEDULER_STOPPED()) { /* * Ensure that spinlock sections are balanced even when the * scheduler is stopped, since we may otherwise inadvertently * re-enable interrupts while dumping core. */ spinlock_enter(); return; } lock_delay_arg_init(&lda, &mtx_spin_delay); #ifdef LOCK_PROFILING doing_lockprof = 1; #elif defined(KDTRACE_HOOKS) doing_lockprof = lockstat_enabled; if (__predict_false(doing_lockprof)) spin_time -= lockstat_nsecs(&td->td_lock->lock_object); #endif for (;;) { retry: v = MTX_UNOWNED; spinlock_enter(); m = td->td_lock; thread_lock_validate(m, opts, file, line); for (;;) { if (_mtx_obtain_lock_fetch(m, &v, tid)) break; if (v == MTX_UNOWNED) continue; if (v == tid) { m->mtx_recurse++; break; } #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); /* Give interrupts a chance while we spin. */ spinlock_exit(); do { if (lda.spin_cnt < 10000000) { lock_delay(&lda); } else { lda.spin_cnt++; if (lda.spin_cnt < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); } if (m != td->td_lock) goto retry; v = MTX_READ_VALUE(m); } while (v != MTX_UNOWNED); spinlock_enter(); } if (m == td->td_lock) break; __mtx_unlock_spin(m); /* does spinlock_exit() */ } LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) if (__predict_true(!doing_lockprof)) return; #endif #ifdef KDTRACE_HOOKS spin_time += lockstat_nsecs(&m->lock_object); #endif if (m->mtx_recurse == 0) LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, contested, waittime, file, line); #ifdef KDTRACE_HOOKS if (lda.spin_cnt != 0) LOCKSTAT_RECORD1(thread__spin, m, spin_time); #endif }
void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v) #endif { struct mtx *m; struct lock_delay_arg lda; uintptr_t tid; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS int64_t spin_time = 0; #endif #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) int doing_lockprof; #endif tid = (uintptr_t)curthread; m = mtxlock2mtx(c); if (__predict_false(v == MTX_UNOWNED)) v = MTX_READ_VALUE(m); if (__predict_false(v == tid)) { m->mtx_recurse++; return; } if (SCHEDULER_STOPPED()) return; lock_delay_arg_init(&lda, &mtx_spin_delay); if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m); KTR_STATE1(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "spinning", "lockname:\"%s\"", m->lock_object.lo_name); #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); #ifdef LOCK_PROFILING doing_lockprof = 1; #elif defined(KDTRACE_HOOKS) doing_lockprof = lockstat_enabled; if (__predict_false(doing_lockprof)) spin_time -= lockstat_nsecs(&m->lock_object); #endif for (;;) { if (v == MTX_UNOWNED) { if (_mtx_obtain_lock_fetch(m, &v, tid)) break; continue; } /* Give interrupts a chance while we spin. */ spinlock_exit(); do { if (lda.spin_cnt < 10000000) { lock_delay(&lda); } else { lda.spin_cnt++; if (lda.spin_cnt < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); } v = MTX_READ_VALUE(m); } while (v != MTX_UNOWNED); spinlock_enter(); } if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m); KTR_STATE0(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "running"); #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) if (__predict_true(!doing_lockprof)) return; #endif #ifdef KDTRACE_HOOKS spin_time += lockstat_nsecs(&m->lock_object); #endif LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, contested, waittime, file, line); #ifdef KDTRACE_HOOKS if (lda.spin_cnt != 0) LOCKSTAT_RECORD1(spin__spin, m, spin_time); #endif }
void thread_lock_flags_(struct thread *td, int opts, const char *file, int line) { struct mtx *m; uintptr_t tid; int i; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS int64_t spin_time = 0; #endif i = 0; tid = (uintptr_t)curthread; if (SCHEDULER_STOPPED()) return; #ifdef KDTRACE_HOOKS spin_time -= lockstat_nsecs(&td->td_lock->lock_object); #endif for (;;) { retry: spinlock_enter(); m = td->td_lock; KASSERT(m->mtx_lock != MTX_DESTROYED, ("thread_lock() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("thread_lock() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); if (mtx_owned(m)) KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0, ("thread_lock: recursed on non-recursive mutex %s @ %s:%d\n", 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)) { if (m->mtx_lock == tid) { m->mtx_recurse++; break; } #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); /* Give interrupts a chance while we spin. */ spinlock_exit(); while (m->mtx_lock != MTX_UNOWNED) { if (i++ < 10000000) cpu_spinwait(); else if (i < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); if (m != td->td_lock) goto retry; } spinlock_enter(); } if (m == td->td_lock) break; __mtx_unlock_spin(m); /* does spinlock_exit() */ } #ifdef KDTRACE_HOOKS spin_time += lockstat_nsecs(&m->lock_object); #endif if (m->mtx_recurse == 0) LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, contested, waittime, file, line); LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); LOCKSTAT_RECORD1(thread__spin, m, spin_time); }
/* * Panic is called on unresolvable fatal errors. It prints "panic: mesg", * and then reboots. If we are called twice, then we avoid trying to sync * the disks as this often leads to recursive panics. */ void panic(const char *fmt, ...) { #ifdef SMP static volatile u_int panic_cpu = NOCPU; cpuset_t other_cpus; #endif struct thread *td = curthread; int bootopt, newpanic; va_list ap; static char buf[256]; if (stop_scheduler_on_panic) spinlock_enter(); else critical_enter(); #ifdef SMP /* * We don't want multiple CPU's to panic at the same time, so we * use panic_cpu as a simple spinlock. We have to keep checking * panic_cpu if we are spinning in case the panic on the first * CPU is canceled. */ if (panic_cpu != PCPU_GET(cpuid)) while (atomic_cmpset_int(&panic_cpu, NOCPU, PCPU_GET(cpuid)) == 0) while (panic_cpu != NOCPU) ; /* nothing */ if (stop_scheduler_on_panic) { if (panicstr == NULL && !kdb_active) { other_cpus = all_cpus; CPU_CLR(PCPU_GET(cpuid), &other_cpus); stop_cpus_hard(other_cpus); } /* * We set stop_scheduler here and not in the block above, * because we want to ensure that if panic has been called and * stop_scheduler_on_panic is true, then stop_scheduler will * always be set. Even if panic has been entered from kdb. */ td->td_stopsched = 1; } #endif bootopt = RB_AUTOBOOT; newpanic = 0; if (panicstr) bootopt |= RB_NOSYNC; else { bootopt |= RB_DUMP; panicstr = fmt; newpanic = 1; } va_start(ap, fmt); if (newpanic) { (void)vsnprintf(buf, sizeof(buf), fmt, ap); panicstr = buf; cngrab(); printf("panic: %s\n", buf); } else { printf("panic: "); vprintf(fmt, ap); printf("\n"); } va_end(ap); #ifdef SMP printf("cpuid = %d\n", PCPU_GET(cpuid)); #endif #ifdef KDB if (newpanic && trace_on_panic) kdb_backtrace(); if (debugger_on_panic) kdb_enter(KDB_WHY_PANIC, "panic"); #endif /*thread_lock(td); */ td->td_flags |= TDF_INPANIC; /* thread_unlock(td); */ if (!sync_on_panic) bootopt |= RB_NOSYNC; if (!stop_scheduler_on_panic) critical_exit(); kern_reboot(bootopt); }