[tip:perf/core] jump_label: Add COND_STMT(), reducer wrappery

tip-bot for Peter Zijlstra
2010-10-18T19:23:07Z

Commit-ID: ebf31f502492527e2b6b5e5cf85a4ebc7fc8a52e
Gitweb: http://git.kernel.org/tip/ebf31f502492527e2b6b5e5cf85a4ebc7fc8a52e
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Sun, 17 Oct 2010 12:15:00 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Mon, 18 Oct 2010 19:59:01 +0200

jump_label: Add COND_STMT(), reducer wrappery

The use of the JUMP_LABEL() construct ends up creating endless silly
wrappers, create a higher level construct to reduce this clutter.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/linux/jump_label.h | 10 ++++++++++
include/linux/perf_event.h | 12 ++----------
2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 81be496..b67cb18 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -61,4 +61,14 @@ static inline int jump_label_text_reserved(void *start, void *end)

#endif

+#define COND_STMT(key, stmt) \
+do { \
+ __label__ jl_enabled; \
+ JUMP_LABEL(key, jl_enabled); \
+ if (0) { \
+jl_enabled: \
+ stmt; \
+ } \
+} while (0)
+
#endif
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 3b80cbf..057bf22 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -903,21 +903,13 @@ 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);
+ COND_STMT(&perf_task_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);
+ COND_STMT(&perf_task_events, __perf_event_task_sched_out(task, next));
}

extern int perf_event_init_task(struct task_struct *child);