perf: Use jump_labels to optimize the scheduler hooks
Trades a call + conditional + ret for an unconditional jmp.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.501657727@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 97965fa..7f0e7f5 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -487,6 +487,7 @@
#include <linux/ftrace.h>
#include <linux/cpu.h>
#include <linux/irq_work.h>
+#include <linux/jump_label_ref.h>
#include <asm/atomic.h>
#include <asm/local.h>
@@ -895,8 +896,30 @@
extern int perf_num_counters(void);
extern const char *perf_pmu_name(void);
-extern void perf_event_task_sched_in(struct task_struct *task);
-extern void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);
+extern void __perf_event_task_sched_in(struct task_struct *task);
+extern void __perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);
+
+extern atomic_t perf_task_events;
+
+static inline void perf_event_task_sched_in(struct task_struct *task)
+{
+ JUMP_LABEL(&perf_task_events, have_events);
+ return;
+
+have_events:
+ __perf_event_task_sched_in(task);
+}
+
+static inline
+void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next)
+{
+ JUMP_LABEL(&perf_task_events, have_events);
+ return;
+
+have_events:
+ __perf_event_task_sched_out(task, next);
+}
+
extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);