perf_pmu_disable(event->pmu);
- event->tstamp_running += tstamp - event->tstamp_stopped;
-
perf_set_shadow_time(event, ctx, tstamp);
perf_log_itrace_start(event);
goto out;
}
+ event->tstamp_running += tstamp - event->tstamp_stopped;
+
if (!is_software_event(event))
cpuctx->active_oncpu++;
if (!ctx->nr_active++)
return __perf_event_count(event);
}
+/*
+ * NMI-safe method to read a local event, that is an event that
+ * is:
+ * - either for the current task, or for this CPU
+ * - does not have inherit set, for inherited task events
+ * will not be local and we cannot read them atomically
+ * - must not have a pmu::count method
+ */
+u64 perf_event_read_local(struct perf_event *event)
+{
+ unsigned long flags;
+ u64 val;
+
+ /*
+ * Disabling interrupts avoids all counter scheduling (context
+ * switches, timer based rotation and IPIs).
+ */
+ local_irq_save(flags);
+
+ /* If this is a per-task event, it must be for current */
+ WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) &&
+ event->hw.target != current);
+
+ /* If this is a per-CPU event, it must be for this CPU */
+ WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) &&
+ event->cpu != smp_processor_id());
+
+ /*
+ * It must not be an event with inherit set, we cannot read
+ * all child counters from atomic context.
+ */
+ WARN_ON_ONCE(event->attr.inherit);
+
+ /*
+ * It must not have a pmu::count method, those are not
+ * NMI safe.
+ */
+ WARN_ON_ONCE(event->pmu->count);
+
+ /*
+ * If the event is currently on this CPU, its either a per-task event,
+ * or local to this CPU. Furthermore it means its ACTIVE (otherwise
+ * oncpu == -1).
+ */
+ if (event->oncpu == smp_processor_id())
+ event->pmu->read(event);
+
+ val = local64_read(&event->count);
+ local_irq_restore(flags);
+
+ return val;
+}
+
static u64 perf_event_read(struct perf_event *event)
{
/*
perf_event_for_each_child(sibling, func);
}
-static int perf_event_period(struct perf_event *event, u64 __user *arg)
-{
- struct perf_event_context *ctx = event->ctx;
- int ret = 0, active;
+struct period_event {
+ struct perf_event *event;
u64 value;
+};
- if (!is_sampling_event(event))
- return -EINVAL;
-
- if (copy_from_user(&value, arg, sizeof(value)))
- return -EFAULT;
-
- if (!value)
- return -EINVAL;
+static int __perf_event_period(void *info)
+{
+ struct period_event *pe = info;
+ struct perf_event *event = pe->event;
+ struct perf_event_context *ctx = event->ctx;
+ u64 value = pe->value;
+ bool active;
- raw_spin_lock_irq(&ctx->lock);
+ raw_spin_lock(&ctx->lock);
if (event->attr.freq) {
- if (value > sysctl_perf_event_sample_rate) {
- ret = -EINVAL;
- goto unlock;
- }
-
event->attr.sample_freq = value;
} else {
event->attr.sample_period = value;
event->pmu->start(event, PERF_EF_RELOAD);
perf_pmu_enable(ctx->pmu);
}
+ raw_spin_unlock(&ctx->lock);
-unlock:
+ return 0;
+}
+
+static int perf_event_period(struct perf_event *event, u64 __user *arg)
+{
+ struct period_event pe = { .event = event, };
+ struct perf_event_context *ctx = event->ctx;
+ struct task_struct *task;
+ u64 value;
+
+ if (!is_sampling_event(event))
+ return -EINVAL;
+
+ if (copy_from_user(&value, arg, sizeof(value)))
+ return -EFAULT;
+
+ if (!value)
+ return -EINVAL;
+
+ if (event->attr.freq && value > sysctl_perf_event_sample_rate)
+ return -EINVAL;
+
+ task = ctx->task;
+ pe.value = value;
+
+ if (!task) {
+ cpu_function_call(event->cpu, __perf_event_period, &pe);
+ return 0;
+ }
+
+retry:
+ if (!task_function_call(task, __perf_event_period, &pe))
+ return 0;
+
+ raw_spin_lock_irq(&ctx->lock);
+ if (ctx->is_active) {
+ raw_spin_unlock_irq(&ctx->lock);
+ task = ctx->task;
+ goto retry;
+ }
+
+ __perf_event_period(&pe);
raw_spin_unlock_irq(&ctx->lock);
- return ret;
+ return 0;
}
static const struct file_operations perf_fops;
* to user-space before waking everybody up.
*/
+static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
+{
+ /* only the parent has fasync state */
+ if (event->parent)
+ event = event->parent;
+ return &event->fasync;
+}
+
void perf_event_wakeup(struct perf_event *event)
{
ring_buffer_wakeup(event);
if (event->pending_kill) {
- kill_fasync(&event->fasync, SIGIO, event->pending_kill);
+ kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
event->pending_kill = 0;
}
}
else
perf_event_output(event, data, regs);
- if (event->fasync && event->pending_kill) {
+ if (*perf_event_fasync(event) && event->pending_kill) {
event->pending_wakeup = 1;
irq_work_queue(&event->pending);
}
WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
}
+struct perf_event *perf_event_get(unsigned int fd)
+{
+ int err;
+ struct fd f;
+ struct perf_event *event;
+
+ err = perf_fget_light(fd, &f);
+ if (err)
+ return ERR_PTR(err);
+
+ event = f.file->private_data;
+ atomic_long_inc(&event->refcount);
+ fdput(f);
+
+ return event;
+}
+
+const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
+{
+ if (!event)
+ return ERR_PTR(-EINVAL);
+
+ return &event->attr;
+}
+
/*
* inherit a event from parent task to child task:
*/
projects / platform / kernel / linux-rpi.git / blobdiff