static void perf_duration_warn(struct irq_work *w)
{
- printk_ratelimited(KERN_WARNING
+ printk_ratelimited(KERN_INFO
"perf: interrupt took too long (%lld > %lld), lowering "
"kernel.perf_event_max_sample_rate to %d\n",
__report_avg, __report_allowed,
static inline int
event_filter_match(struct perf_event *event)
{
- return (event->cpu == -1 || event->cpu == smp_processor_id())
- && perf_cgroup_match(event) && pmu_filter_match(event);
+ return (event->cpu == -1 || event->cpu == smp_processor_id()) &&
+ perf_cgroup_match(event) && pmu_filter_match(event);
}
static void
* maintained, otherwise bogus information is return
* via read() for time_enabled, time_running:
*/
- if (event->state == PERF_EVENT_STATE_INACTIVE
- && !event_filter_match(event)) {
+ if (event->state == PERF_EVENT_STATE_INACTIVE &&
+ !event_filter_match(event)) {
delta = tstamp - event->tstamp_stopped;
event->tstamp_running += delta;
event->tstamp_stopped = tstamp;
lockdep_assert_held(&ctx->mutex);
- event->ctx = ctx;
if (event->cpu != -1)
event->cpu = cpu;
+ /*
+ * Ensures that if we can observe event->ctx, both the event and ctx
+ * will be 'complete'. See perf_iterate_sb_cpu().
+ */
+ smp_store_release(&event->ctx, ctx);
+
if (!task) {
cpu_function_call(cpu, __perf_install_in_context, event);
return;
struct perf_event *event;
list_for_each_entry_rcu(event, &pel->list, sb_list) {
+ /*
+ * Skip events that are not fully formed yet; ensure that
+ * if we observe event->ctx, both event and ctx will be
+ * complete enough. See perf_install_in_context().
+ */
+ if (!smp_load_acquire(&event->ctx))
+ continue;
+
if (event->state < PERF_EVENT_STATE_INACTIVE)
continue;
if (!event_filter_match(event))
}
}
-static void perf_event_init_cpu(int cpu)
+int perf_event_init_cpu(unsigned int cpu)
{
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
rcu_assign_pointer(swhash->swevent_hlist, hlist);
}
mutex_unlock(&swhash->hlist_mutex);
+ return 0;
}
#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
}
srcu_read_unlock(&pmus_srcu, idx);
}
+#else
+
+static void perf_event_exit_cpu_context(int cpu) { }
-static void perf_event_exit_cpu(int cpu)
+#endif
+
+int perf_event_exit_cpu(unsigned int cpu)
{
perf_event_exit_cpu_context(cpu);
+ return 0;
}
-#else
-static inline void perf_event_exit_cpu(int cpu) { }
-#endif
static int
perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
.priority = INT_MIN,
};
-static int
-perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
-{
- unsigned int cpu = (long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
-
- case CPU_UP_PREPARE:
- /*
- * This must be done before the CPU comes alive, because the
- * moment we can run tasks we can encounter (software) events.
- *
- * Specifically, someone can have inherited events on kthreadd
- * or a pre-existing worker thread that gets re-bound.
- */
- perf_event_init_cpu(cpu);
- break;
-
- case CPU_DOWN_PREPARE:
- /*
- * This must be done before the CPU dies because after that an
- * active event might want to IPI the CPU and that'll not work
- * so great for dead CPUs.
- *
- * XXX smp_call_function_single() return -ENXIO without a warn
- * so we could possibly deal with this.
- *
- * This is safe against new events arriving because
- * sys_perf_event_open() serializes against hotplug using
- * get_online_cpus().
- */
- perf_event_exit_cpu(cpu);
- break;
- default:
- break;
- }
-
- return NOTIFY_OK;
-}
-
void __init perf_event_init(void)
{
int ret;
perf_pmu_register(&perf_cpu_clock, NULL, -1);
perf_pmu_register(&perf_task_clock, NULL, -1);
perf_tp_register();
- perf_cpu_notifier(perf_cpu_notify);
+ perf_event_init_cpu(smp_processor_id());
register_reboot_notifier(&perf_reboot_notifier);
ret = init_hw_breakpoint();