From: Minho Ban <mhban@samsung.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Paul Turner <pjt@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Josh Triplett <josh@joshtriplett.org>
Subject: [PATCH] tracing: Prevent wasting time evaluating parameters in trace_preempt_on/off
Date: Wed, 25 Apr 2012 14:33:32 +0900 [thread overview]
Message-ID: <4F978CAC.6060408@samsung.com> (raw)
This fixes spending time for evaluating parameters in trace_preempt_on/off when
the tracer config is off.
The patch mainly inspired by Steven Rostedt, thanks Steven.
Signed-off-by: Minho Ban <mhban@samsung.com>
---
include/linux/ftrace.h | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 72a6cab..bc7af66 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -485,8 +485,12 @@ static inline void __ftrace_enabled_restore(int enabled)
extern void trace_preempt_on(unsigned long a0, unsigned long a1);
extern void trace_preempt_off(unsigned long a0, unsigned long a1);
#else
- static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { }
- static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { }
+/*
+ * Use defines instead of static inlines because some arches will make code out
+ * of the CALLER_ADDR, when we really want these to be a real nop.
+ */
+# define trace_preempt_on(a0, a1) do { } while (0)
+# define trace_preempt_off(a0, a1) do { } while (0)
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
--
1.7.5.4
next reply other threads:[~2012-04-25 5:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-25 5:33 Minho Ban [this message]
2012-04-25 11:10 ` [PATCH] tracing: Prevent wasting time evaluating parameters in trace_preempt_on/off Steven Rostedt
-- strict thread matches above, loose matches on Subject: below --
2012-05-07 2:36 Minho Ban
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