diff options
Diffstat (limited to 'kernel/events/core.c')
| -rw-r--r-- | kernel/events/core.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 3f07e6cfc1b6..dff00c787867 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3578,10 +3578,18 @@ static int perf_event_read(struct perf_event *event, bool group) cpu_to_read = find_cpu_to_read(event, local_cpu); put_cpu(); - ret = smp_call_function_single(cpu_to_read, __perf_event_read, &data, 1); - /* The event must have been read from an online CPU: */ - WARN_ON_ONCE(ret); - ret = ret ? : data.ret; + /* + * Purposely ignore the smp_call_function_single() return + * value. + * + * If event->oncpu isn't a valid CPU it means the event got + * scheduled out and that will have updated the event count. + * + * Therefore, either way, we'll have an up-to-date event count + * after this. + */ + (void)smp_call_function_single(cpu_to_read, __perf_event_read, &data, 1); + ret = data.ret; } else if (event->state == PERF_EVENT_STATE_INACTIVE) { struct perf_event_context *ctx = event->ctx; unsigned long flags; @@ -6196,7 +6204,7 @@ static int __perf_pmu_output_stop(void *info) { struct perf_event *event = info; struct pmu *pmu = event->pmu; - struct perf_cpu_context *cpuctx = get_cpu_ptr(pmu->pmu_cpu_context); + struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context); struct remote_output ro = { .rb = event->rb, }; |