+ /*
+ * 32 bit flags:
+ * bit 1: enabled
+ * bit 2: filter_active
+ *
+ * Changes to flags must hold the event_mutex.
+ *
+ * Note: Reads of flags do not hold the event_mutex since
+ * they occur in critical sections. But the way flags
+ * is currently used, these changes do no affect the code
+ * except that when a change is made, it may have a slight
+ * delay in propagating the changes to other CPUs due to
+ * caching and such.
+ */
+ unsigned int flags;
+
+#ifdef CONFIG_PERF_EVENTS