1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 057bf22a8323..40150f345982 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -747,6 +747,16 @@ struct perf_event {
         u64                             tstamp_running;
         u64                             tstamp_stopped;
 
+        /*
+         * 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.
+         *
+         * ctx_time already accounts for ctx->timestamp. Therefore to
+         * compute ctx_time for a sample, simply add perf_clock().
+         */
+        u64                             shadow_ctx_time;
+
         struct perf_event_attr          attr;
         struct hw_perf_event            hw;