1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index cae4a9481777..9fc9b0d31442 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -272,6 +272,11 @@ struct pmu {
          */
         size_t                          task_ctx_size;
 
+
+        /*
+         * Return the count value for a counter.
+         */
+        u64 (*count)                    (struct perf_event *event); /*optional*/
 };
 
 /**
@@ -770,6 +775,11 @@ static inline void perf_event_task_sched_out(struct task_struct *prev,
                 __perf_event_task_sched_out(prev, next);
 }
 
+static inline u64 __perf_event_count(struct perf_event *event)
+{
+        return local64_read(&event->count) + atomic64_read(&event->child_count);
+}
+
 extern void perf_event_mmap(struct vm_area_struct *vma);
 extern struct perf_guest_info_callbacks *perf_guest_cbs;
 extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);