diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 5c6fae4f43d8..ff854fd89a81 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -2666,6 +2666,7 @@ static void perf_counter_output(struct perf_counter *counter, int nmi,
 		header.size += sizeof(cpu_entry);
 
 		cpu_entry.cpu = raw_smp_processor_id();
+		cpu_entry.reserved = 0;
 	}
 
 	if (sample_type & PERF_SAMPLE_PERIOD)