perf: Optimize sw events

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 7f0e7f5..3b80cbf 100644 (file)
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1012,18 +1012,20 @@ static inline void perf_fetch_caller_regs(struct pt_regs *regs)
        perf_arch_fetch_caller_regs(regs, CALLER_ADDR0);
 }
 
-static inline void
+static __always_inline void
 perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
 {
-       if (atomic_read(&perf_swevent_enabled[event_id])) {
-               struct pt_regs hot_regs;
-
-               if (!regs) {
-                       perf_fetch_caller_regs(&hot_regs);
-                       regs = &hot_regs;
-               }
-               __perf_sw_event(event_id, nr, nmi, regs, addr);
+       struct pt_regs hot_regs;
+
+       JUMP_LABEL(&perf_swevent_enabled[event_id], have_event);
+       return;
+
+have_event:
+       if (!regs) {
+               perf_fetch_caller_regs(&hot_regs);
+               regs = &hot_regs;
        }
+       __perf_sw_event(event_id, nr, nmi, regs, addr);
 }
 
 extern void perf_event_mmap(struct vm_area_struct *vma);

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index f7febb0..05ecf6f 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4669,7 +4669,7 @@ static void sw_perf_event_destroy(struct perf_event *event)
 
        WARN_ON(event->parent);
 
-       atomic_dec(&perf_swevent_enabled[event_id]);
+       jump_label_dec(&perf_swevent_enabled[event_id]);
        swevent_hlist_put(event);
 }
 
@@ -4699,7 +4699,7 @@ static int perf_swevent_init(struct perf_event *event)
                if (err)
                        return err;
 
-               atomic_inc(&perf_swevent_enabled[event_id]);
+               jump_label_inc(&perf_swevent_enabled[event_id]);
                event->destroy = sw_perf_event_destroy;
        }