void __weak hw_perf_event_setup(int cpu) { barrier(); }
void __weak hw_perf_event_setup_online(int cpu) { barrier(); }
+void __weak hw_perf_event_setup_offline(int cpu) { barrier(); }
int __weak
hw_perf_group_sched_in(struct perf_event *group_leader,
struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx, int cpu)
+ struct perf_event_context *ctx)
{
return 0;
}
static inline u64 perf_clock(void)
{
- return cpu_clock(smp_processor_id());
+ return cpu_clock(raw_smp_processor_id());
}
/*
static int
event_sched_in(struct perf_event *event,
struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx,
- int cpu)
+ struct perf_event_context *ctx)
{
if (event->state <= PERF_EVENT_STATE_OFF)
return 0;
event->state = PERF_EVENT_STATE_ACTIVE;
- event->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */
+ event->oncpu = smp_processor_id();
/*
* The new state must be visible before we turn it on in the hardware:
*/
static int
group_sched_in(struct perf_event *group_event,
struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx,
- int cpu)
+ struct perf_event_context *ctx)
{
struct perf_event *event, *partial_group;
int ret;
if (group_event->state == PERF_EVENT_STATE_OFF)
return 0;
- ret = hw_perf_group_sched_in(group_event, cpuctx, ctx, cpu);
+ ret = hw_perf_group_sched_in(group_event, cpuctx, ctx);
if (ret)
return ret < 0 ? ret : 0;
- if (event_sched_in(group_event, cpuctx, ctx, cpu))
+ if (event_sched_in(group_event, cpuctx, ctx))
return -EAGAIN;
/*
* Schedule in siblings as one group (if any):
*/
list_for_each_entry(event, &group_event->sibling_list, group_entry) {
- if (event_sched_in(event, cpuctx, ctx, cpu)) {
+ if (event_sched_in(event, cpuctx, ctx)) {
partial_group = event;
goto group_error;
}
struct perf_event *event = info;
struct perf_event_context *ctx = event->ctx;
struct perf_event *leader = event->group_leader;
- int cpu = smp_processor_id();
int err;
/*
if (!group_can_go_on(event, cpuctx, 1))
err = -EEXIST;
else
- err = event_sched_in(event, cpuctx, ctx, cpu);
+ err = event_sched_in(event, cpuctx, ctx);
if (err) {
/*
} else {
perf_disable();
if (event == leader)
- err = group_sched_in(event, cpuctx, ctx,
- smp_processor_id());
+ err = group_sched_in(event, cpuctx, ctx);
else
- err = event_sched_in(event, cpuctx, ctx,
- smp_processor_id());
+ err = event_sched_in(event, cpuctx, ctx);
perf_enable();
}
static void
ctx_pinned_sched_in(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx,
- int cpu)
+ struct perf_cpu_context *cpuctx)
{
struct perf_event *event;
list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
if (event->state <= PERF_EVENT_STATE_OFF)
continue;
- if (event->cpu != -1 && event->cpu != cpu)
+ if (event->cpu != -1 && event->cpu != smp_processor_id())
continue;
if (group_can_go_on(event, cpuctx, 1))
- group_sched_in(event, cpuctx, ctx, cpu);
+ group_sched_in(event, cpuctx, ctx);
/*
* If this pinned group hasn't been scheduled,
static void
ctx_flexible_sched_in(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx,
- int cpu)
+ struct perf_cpu_context *cpuctx)
{
struct perf_event *event;
int can_add_hw = 1;
* Listen to the 'cpu' scheduling filter constraint
* of events:
*/
- if (event->cpu != -1 && event->cpu != cpu)
+ if (event->cpu != -1 && event->cpu != smp_processor_id())
continue;
if (group_can_go_on(event, cpuctx, can_add_hw))
- if (group_sched_in(event, cpuctx, ctx, cpu))
+ if (group_sched_in(event, cpuctx, ctx))
can_add_hw = 0;
}
}
struct perf_cpu_context *cpuctx,
enum event_type_t event_type)
{
- int cpu = smp_processor_id();
-
raw_spin_lock(&ctx->lock);
ctx->is_active = 1;
if (likely(!ctx->nr_events))
* in order to give them the best chance of going on.
*/
if (event_type & EVENT_PINNED)
- ctx_pinned_sched_in(ctx, cpuctx, cpu);
+ ctx_pinned_sched_in(ctx, cpuctx);
/* Then walk through the lower prio flexible groups */
if (event_type & EVENT_FLEXIBLE)
- ctx_flexible_sched_in(ctx, cpuctx, cpu);
+ ctx_flexible_sched_in(ctx, cpuctx);
perf_enable();
out:
raw_spin_unlock(&ctx->lock);
}
+static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
+ enum event_type_t event_type)
+{
+ struct perf_event_context *ctx = &cpuctx->ctx;
+
+ ctx_sched_in(ctx, cpuctx, event_type);
+}
+
static void task_ctx_sched_in(struct task_struct *task,
enum event_type_t event_type)
{
*/
void perf_event_task_sched_in(struct task_struct *task)
{
- task_ctx_sched_in(task, EVENT_ALL);
-}
+ struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+ struct perf_event_context *ctx = task->perf_event_ctxp;
-static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
- enum event_type_t event_type)
-{
- struct perf_event_context *ctx = &cpuctx->ctx;
+ if (likely(!ctx))
+ return;
- ctx_sched_in(ctx, cpuctx, event_type);
+ if (cpuctx->task_ctx == ctx)
+ return;
+
+ /*
+ * We want to keep the following priority order:
+ * cpu pinned (that don't need to move), task pinned,
+ * cpu flexible, task flexible.
+ */
+ cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+
+ ctx_sched_in(ctx, cpuctx, EVENT_PINNED);
+ cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE);
+ ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE);
+
+ cpuctx->task_ctx = ctx;
}
#define MAX_INTERRUPTS (~0ULL)
static void perf_log_throttle(struct perf_event *event, int enable);
-static void perf_adjust_period(struct perf_event *event, u64 events)
+static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
+{
+ u64 frequency = event->attr.sample_freq;
+ u64 sec = NSEC_PER_SEC;
+ u64 divisor, dividend;
+
+ int count_fls, nsec_fls, frequency_fls, sec_fls;
+
+ count_fls = fls64(count);
+ nsec_fls = fls64(nsec);
+ frequency_fls = fls64(frequency);
+ sec_fls = 30;
+
+ /*
+ * We got @count in @nsec, with a target of sample_freq HZ
+ * the target period becomes:
+ *
+ * @count * 10^9
+ * period = -------------------
+ * @nsec * sample_freq
+ *
+ */
+
+ /*
+ * Reduce accuracy by one bit such that @a and @b converge
+ * to a similar magnitude.
+ */
+#define REDUCE_FLS(a, b) \
+do { \
+ if (a##_fls > b##_fls) { \
+ a >>= 1; \
+ a##_fls--; \
+ } else { \
+ b >>= 1; \
+ b##_fls--; \
+ } \
+} while (0)
+
+ /*
+ * Reduce accuracy until either term fits in a u64, then proceed with
+ * the other, so that finally we can do a u64/u64 division.
+ */
+ while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
+ REDUCE_FLS(nsec, frequency);
+ REDUCE_FLS(sec, count);
+ }
+
+ if (count_fls + sec_fls > 64) {
+ divisor = nsec * frequency;
+
+ while (count_fls + sec_fls > 64) {
+ REDUCE_FLS(count, sec);
+ divisor >>= 1;
+ }
+
+ dividend = count * sec;
+ } else {
+ dividend = count * sec;
+
+ while (nsec_fls + frequency_fls > 64) {
+ REDUCE_FLS(nsec, frequency);
+ dividend >>= 1;
+ }
+
+ divisor = nsec * frequency;
+ }
+
+ return div64_u64(dividend, divisor);
+}
+
+static void perf_event_stop(struct perf_event *event)
+{
+ if (!event->pmu->stop)
+ return event->pmu->disable(event);
+
+ return event->pmu->stop(event);
+}
+
+static int perf_event_start(struct perf_event *event)
+{
+ if (!event->pmu->start)
+ return event->pmu->enable(event);
+
+ return event->pmu->start(event);
+}
+
+static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count)
{
struct hw_perf_event *hwc = &event->hw;
u64 period, sample_period;
s64 delta;
- events *= hwc->sample_period;
- period = div64_u64(events, event->attr.sample_freq);
+ period = perf_calculate_period(event, nsec, count);
delta = (s64)(period - hwc->sample_period);
delta = (delta + 7) / 8; /* low pass filter */
sample_period = 1;
hwc->sample_period = sample_period;
+
+ if (atomic64_read(&hwc->period_left) > 8*sample_period) {
+ perf_disable();
+ perf_event_stop(event);
+ atomic64_set(&hwc->period_left, 0);
+ perf_event_start(event);
+ perf_enable();
+ }
}
static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
{
struct perf_event *event;
struct hw_perf_event *hwc;
- u64 interrupts, freq;
+ u64 interrupts, now;
+ s64 delta;
raw_spin_lock(&ctx->lock);
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
if (interrupts == MAX_INTERRUPTS) {
perf_log_throttle(event, 1);
event->pmu->unthrottle(event);
- interrupts = 2*sysctl_perf_event_sample_rate/HZ;
}
if (!event->attr.freq || !event->attr.sample_freq)
continue;
- /*
- * if the specified freq < HZ then we need to skip ticks
- */
- if (event->attr.sample_freq < HZ) {
- freq = event->attr.sample_freq;
-
- hwc->freq_count += freq;
- hwc->freq_interrupts += interrupts;
-
- if (hwc->freq_count < HZ)
- continue;
-
- interrupts = hwc->freq_interrupts;
- hwc->freq_interrupts = 0;
- hwc->freq_count -= HZ;
- } else
- freq = HZ;
-
- perf_adjust_period(event, freq * interrupts);
+ event->pmu->read(event);
+ now = atomic64_read(&event->count);
+ delta = now - hwc->freq_count_stamp;
+ hwc->freq_count_stamp = now;
- /*
- * In order to avoid being stalled by an (accidental) huge
- * sample period, force reset the sample period if we didn't
- * get any events in this freq period.
- */
- if (!interrupts) {
- perf_disable();
- event->pmu->disable(event);
- atomic64_set(&hwc->period_left, 0);
- event->pmu->enable(event);
- perf_enable();
- }
+ if (delta > 0)
+ perf_adjust_period(event, TICK_NSEC, delta);
}
raw_spin_unlock(&ctx->lock);
}
raw_spin_lock(&ctx->lock);
/* Rotate the first entry last of non-pinned groups */
- perf_disable();
-
list_rotate_left(&ctx->flexible_groups);
- perf_enable();
-
raw_spin_unlock(&ctx->lock);
}
cpuctx = &__get_cpu_var(perf_cpu_context);
ctx = curr->perf_event_ctxp;
+ perf_disable();
+
perf_ctx_adjust_freq(&cpuctx->ctx);
if (ctx)
perf_ctx_adjust_freq(ctx);
cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE);
if (ctx)
task_ctx_sched_in(curr, EVENT_FLEXIBLE);
+
+ perf_enable();
}
static int event_enable_on_exec(struct perf_event *event,
task_event->event_id.tid = perf_event_tid(event, task);
task_event->event_id.ptid = perf_event_tid(event, current);
- task_event->event_id.time = perf_clock();
-
perf_output_put(&handle, task_event->event_id);
perf_output_end(&handle);
static int perf_event_task_match(struct perf_event *event)
{
+ if (event->state < PERF_EVENT_STATE_INACTIVE)
+ return 0;
+
if (event->cpu != -1 && event->cpu != smp_processor_id())
return 0;
cpuctx = &get_cpu_var(perf_cpu_context);
perf_event_task_ctx(&cpuctx->ctx, task_event);
if (!ctx)
- ctx = rcu_dereference(task_event->task->perf_event_ctxp);
+ ctx = rcu_dereference(current->perf_event_ctxp);
if (ctx)
perf_event_task_ctx(ctx, task_event);
put_cpu_var(perf_cpu_context);
/* .ppid */
/* .tid */
/* .ptid */
+ .time = perf_clock(),
},
};
static int perf_event_comm_match(struct perf_event *event)
{
+ if (event->state < PERF_EVENT_STATE_INACTIVE)
+ return 0;
+
if (event->cpu != -1 && event->cpu != smp_processor_id())
return 0;
static int perf_event_mmap_match(struct perf_event *event,
struct perf_mmap_event *mmap_event)
{
+ if (event->state < PERF_EVENT_STATE_INACTIVE)
+ return 0;
+
if (event->cpu != -1 && event->cpu != smp_processor_id())
return 0;
/* .tid */
.start = vma->vm_start,
.len = vma->vm_end - vma->vm_start,
- .pgoff = vma->vm_pgoff,
+ .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
},
};
if (event->attr.freq) {
u64 now = perf_clock();
- s64 delta = now - hwc->freq_stamp;
+ s64 delta = now - hwc->freq_time_stamp;
- hwc->freq_stamp = now;
+ hwc->freq_time_stamp = now;
- if (delta > 0 && delta < TICK_NSEC)
- perf_adjust_period(event, NSEC_PER_SEC / (int)delta);
+ if (delta > 0 && delta < 2*TICK_NSEC)
+ perf_adjust_period(event, delta, hwc->last_period);
}
/*
if (attr->type >= PERF_TYPE_MAX)
return -EINVAL;
- if (attr->__reserved_1 || attr->__reserved_2)
+ if (attr->__reserved_1)
return -EINVAL;
if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
else
child_event->state = PERF_EVENT_STATE_OFF;
- if (parent_event->attr.freq)
- child_event->hw.sample_period = parent_event->hw.sample_period;
+ if (parent_event->attr.freq) {
+ u64 sample_period = parent_event->hw.sample_period;
+ struct hw_perf_event *hwc = &child_event->hw;
+
+ hwc->sample_period = sample_period;
+ hwc->last_period = sample_period;
+
+ atomic64_set(&hwc->period_left, sample_period);
+ }
child_event->overflow_handler = parent_event->overflow_handler;
perf_event_exit_cpu(cpu);
break;
+ case CPU_DEAD:
+ hw_perf_event_setup_offline(cpu);
+ break;
+
default:
break;
}