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-rw-r--r--include/linux/perf_event.h4
-rw-r--r--kernel/events/core.c34
2 files changed, 33 insertions, 5 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index fe156a8170aa..9b60bb89d86a 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -683,7 +683,9 @@ struct perf_event {
/*
* timestamp shadows the actual context timing but it can
* be safely used in NMI interrupt context. It reflects the
- * context time as it was when the event was last scheduled in.
+ * context time as it was when the event was last scheduled in,
+ * or when ctx_sched_in failed to schedule the event because we
+ * run out of PMC.
*
* ctx_time already accounts for ctx->timestamp. Therefore to
* compute ctx_time for a sample, simply add perf_clock().
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0c000cb01eeb..f23ca260307f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3707,6 +3707,29 @@ static noinline int visit_groups_merge(struct perf_cpu_context *cpuctx,
return 0;
}
+static inline bool event_update_userpage(struct perf_event *event)
+{
+ if (likely(!atomic_read(&event->mmap_count)))
+ return false;
+
+ perf_event_update_time(event);
+ perf_set_shadow_time(event, event->ctx);
+ perf_event_update_userpage(event);
+
+ return true;
+}
+
+static inline void group_update_userpage(struct perf_event *group_event)
+{
+ struct perf_event *event;
+
+ if (!event_update_userpage(group_event))
+ return;
+
+ for_each_sibling_event(event, group_event)
+ event_update_userpage(event);
+}
+
static int merge_sched_in(struct perf_event *event, void *data)
{
struct perf_event_context *ctx = event->ctx;
@@ -3725,14 +3748,15 @@ static int merge_sched_in(struct perf_event *event, void *data)
}
if (event->state == PERF_EVENT_STATE_INACTIVE) {
+ *can_add_hw = 0;
if (event->attr.pinned) {
perf_cgroup_event_disable(event, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
+ } else {
+ ctx->rotate_necessary = 1;
+ perf_mux_hrtimer_restart(cpuctx);
+ group_update_userpage(event);
}
-
- *can_add_hw = 0;
- ctx->rotate_necessary = 1;
- perf_mux_hrtimer_restart(cpuctx);
}
return 0;
@@ -6324,6 +6348,8 @@ accounting:
ring_buffer_attach(event, rb);
+ perf_event_update_time(event);
+ perf_set_shadow_time(event, event->ctx);
perf_event_init_userpage(event);
perf_event_update_userpage(event);
} else {