perf/core: Remove WARN from perf_event_read()

[platform/kernel/linux-starfive.git] / kernel / events / core.c

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5650f53..07ac859 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3549,10 +3549,18 @@ static int perf_event_read(struct perf_event *event, bool group)
                        .group = group,
                        .ret = 0,
                };
-               ret = smp_call_function_single(event->oncpu, __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(event->oncpu, __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;
@@ -6166,7 +6174,7 @@ 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,
        };