[tip:perf/core] perf: Optimize sw events

tip-bot for Peter Zijlstra
2010-10-18T19:22:36Z

Commit-ID: 7e54a5a0b655734326dc78c2b5efc1eb35497bb6
Gitweb: http://git.kernel.org/tip/7e54a5a0b655734326dc78c2b5efc1eb35497bb6
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 14 Oct 2010 22:32:45 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Mon, 18 Oct 2010 19:58:59 +0200

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>
---
include/linux/perf_event.h | 20 +++++++++++---------
kernel/perf_event.c | 4 ++--
2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 7f0e7f5..3b80cbf 100644
--- 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
--- 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;
}