perf counters: add prctl interface to disable/enable counters
Add a way for self-monitoring tasks to disable/enable counters summarily,
via a prctl:
PR_TASK_PERF_COUNTERS_DISABLE 31
PR_TASK_PERF_COUNTERS_ENABLE 32
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 30c0ec8..97d86c2 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -213,6 +213,8 @@
extern void hw_perf_restore(u64 ctrl);
extern void atomic64_counter_set(struct perf_counter *counter, u64 val64);
extern u64 atomic64_counter_read(struct perf_counter *counter);
+extern int perf_counter_task_disable(void);
+extern int perf_counter_task_enable(void);
#else
static inline void
@@ -226,6 +228,8 @@
static inline void perf_counter_print_debug(void) { }
static inline void hw_perf_restore(u64 ctrl) { }
static inline u64 hw_perf_save_disable(void) { return 0; }
+static inline int perf_counter_task_disable(void) { return -EINVAL; }
+static inline int perf_counter_task_enable(void) { return -EINVAL; }
#endif
#endif /* _LINUX_PERF_COUNTER_H */
diff --git a/include/linux/prctl.h b/include/linux/prctl.h
index 48d887e..b00df4c 100644
--- a/include/linux/prctl.h
+++ b/include/linux/prctl.h
@@ -85,4 +85,7 @@
#define PR_SET_TIMERSLACK 29
#define PR_GET_TIMERSLACK 30
+#define PR_TASK_PERF_COUNTERS_DISABLE 31
+#define PR_TASK_PERF_COUNTERS_ENABLE 32
+
#endif /* _LINUX_PRCTL_H */