[RFC][PATCH 06/10] sched: Remove unlikely() from rt_policy() in sched.c

[Steven Rostedt]

From: Steven Rostedt <srostedt@xxxxxxxxxx>

The rt_policy() has an unlikely() that the policy it is checking is
of RT priority (SCHED_FIFO or SCHED_RR).

According to the annotate branch profiler it is incorrect most of the time:

 correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
   36667   654674  94 rt_policy                      sched.c              126

This makes sense because the rt_policy() is used by the sched_set_scheduler()
and nice(). Although users may use sys_nice a bit, all RT users use
the sched_set_scheduler() to set their RT priority, including kernel
threads.

The above numbers were from a normal desktop computer running
firefox, evolution, xchat and was part of a distcc compile farm.

Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 kernel/sched.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index dc91a4d..269a045 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -123,7 +123,7 @@
 
 static inline int rt_policy(int policy)
 {
-	if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR))
+	if (policy == SCHED_FIFO || policy == SCHED_RR)
 		return 1;
 	return 0;
 }
-- 
1.7.2.3


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