diff options
| -rw-r--r-- | arch/i386/kernel/tsc.c | 1 | ||||
| -rw-r--r-- | drivers/acpi/processor_idle.c | 32 | ||||
| -rw-r--r-- | include/linux/sched.h | 3 | ||||
| -rw-r--r-- | kernel/sched.c | 41 | ||||
| -rw-r--r-- | kernel/sched_debug.c | 3 |
5 files changed, 61 insertions, 19 deletions
diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c index debd7db..a39280b 100644 --- a/arch/i386/kernel/tsc.c +++ b/arch/i386/kernel/tsc.c @@ -292,7 +292,6 @@ static struct clocksource clocksource_tsc = { void mark_tsc_unstable(char *reason) { - sched_clock_unstable_event(); if (!tsc_unstable) { tsc_unstable = 1; tsc_enabled = 0; diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index a8634a0..d9b8af7 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -63,6 +63,7 @@ ACPI_MODULE_NAME("processor_idle"); #define ACPI_PROCESSOR_FILE_POWER "power" #define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000) +#define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY) #define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */ #define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */ static void (*pm_idle_save) (void) __read_mostly; @@ -462,6 +463,9 @@ static void acpi_processor_idle(void) * TBD: Can't get time duration while in C1, as resumes * go to an ISR rather than here. Need to instrument * base interrupt handler. + * + * Note: the TSC better not stop in C1, sched_clock() will + * skew otherwise. */ sleep_ticks = 0xFFFFFFFF; break; @@ -469,6 +473,8 @@ static void acpi_processor_idle(void) case ACPI_STATE_C2: /* Get start time (ticks) */ t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); + /* Tell the scheduler that we are going deep-idle: */ + sched_clock_idle_sleep_event(); /* Invoke C2 */ acpi_state_timer_broadcast(pr, cx, 1); acpi_cstate_enter(cx); @@ -479,17 +485,22 @@ static void acpi_processor_idle(void) /* TSC halts in C2, so notify users */ mark_tsc_unstable("possible TSC halt in C2"); #endif + /* Compute time (ticks) that we were actually asleep */ + sleep_ticks = ticks_elapsed(t1, t2); + + /* Tell the scheduler how much we idled: */ + sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); + /* Re-enable interrupts */ local_irq_enable(); + /* Do not account our idle-switching overhead: */ + sleep_ticks -= cx->latency_ticks + C2_OVERHEAD; + current_thread_info()->status |= TS_POLLING; - /* Compute time (ticks) that we were actually asleep */ - sleep_ticks = - ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD; acpi_state_timer_broadcast(pr, cx, 0); break; case ACPI_STATE_C3: - /* * disable bus master * bm_check implies we need ARB_DIS @@ -518,6 +529,8 @@ static void acpi_processor_idle(void) t1 = inl(acpi_gbl_FADT.xpm_timer_block.address); /* Invoke C3 */ acpi_state_timer_broadcast(pr, cx, 1); + /* Tell the scheduler that we are going deep-idle: */ + sched_clock_idle_sleep_event(); acpi_cstate_enter(cx); /* Get end time (ticks) */ t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); @@ -531,12 +544,17 @@ static void acpi_processor_idle(void) /* TSC halts in C3, so notify users */ mark_tsc_unstable("TSC halts in C3"); #endif + /* Compute time (ticks) that we were actually asleep */ + sleep_ticks = ticks_elapsed(t1, t2); + /* Tell the scheduler how much we idled: */ + sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS); + /* Re-enable interrupts */ local_irq_enable(); + /* Do not account our idle-switching overhead: */ + sleep_ticks -= cx->latency_ticks + C3_OVERHEAD; + current_thread_info()->status |= TS_POLLING; - /* Compute time (ticks) that we were actually asleep */ - sleep_ticks = - ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD; acpi_state_timer_broadcast(pr, cx, 0); break; diff --git a/include/linux/sched.h b/include/linux/sched.h index 682ef87..1845b2e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1388,7 +1388,8 @@ extern void sched_exec(void); #define sched_exec() {} #endif -extern void sched_clock_unstable_event(void); +extern void sched_clock_idle_sleep_event(void); +extern void sched_clock_idle_wakeup_event(u64 delta_ns); #ifdef CONFIG_HOTPLUG_CPU extern void idle_task_exit(void); diff --git a/kernel/sched.c b/kernel/sched.c index 45e17b8..48e7586 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -262,7 +262,8 @@ struct rq { s64 clock_max_delta; unsigned int clock_warps, clock_overflows; - unsigned int clock_unstable_events; + u64 idle_clock; + unsigned int clock_deep_idle_events; u64 tick_timestamp; atomic_t nr_iowait; @@ -556,18 +557,40 @@ static inline struct rq *this_rq_lock(void) } /* - * CPU frequency is/was unstable - start new by setting prev_clock_raw: + * We are going deep-idle (irqs are disabled): */ -void sched_clock_unstable_event(void) +void sched_clock_idle_sleep_event(void) { - unsigned long flags; - struct rq *rq; + struct rq *rq = cpu_rq(smp_processor_id()); - rq = task_rq_lock(current, &flags); - rq->prev_clock_raw = sched_clock(); - rq->clock_unstable_events++; - task_rq_unlock(rq, &flags); + spin_lock(&rq->lock); + __update_rq_clock(rq); + spin_unlock(&rq->lock); + rq->clock_deep_idle_events++; +} +EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event); + +/* + * We just idled delta nanoseconds (called with irqs disabled): + */ +void sched_clock_idle_wakeup_event(u64 delta_ns) +{ + struct rq *rq = cpu_rq(smp_processor_id()); + u64 now = sched_clock(); + + rq->idle_clock += delta_ns; + /* + * Override the previous timestamp and ignore all + * sched_clock() deltas that occured while we idled, + * and use the PM-provided delta_ns to advance the + * rq clock: + */ + spin_lock(&rq->lock); + rq->prev_clock_raw = now; + rq->clock += delta_ns; + spin_unlock(&rq->lock); } +EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event); /* * resched_task - mark a task 'to be rescheduled now'. diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 87e5247..ab18f45 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -154,10 +154,11 @@ static void print_cpu(struct seq_file *m, int cpu) P(next_balance); P(curr->pid); P(clock); + P(idle_clock); P(prev_clock_raw); P(clock_warps); P(clock_overflows); - P(clock_unstable_events); + P(clock_deep_idle_events); P(clock_max_delta); P(cpu_load[0]); P(cpu_load[1]); |
