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>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 30c0ec8c1ee3..97d86c293ee8 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -213,6 +213,8 @@ extern u64 hw_perf_save_disable(void);
 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_notify(struct pt_regs *regs)		{ }
 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 */