[PATCH v2] sched: fix unlikely use of sched_info_on()

[PATCH v2] sched: fix unlikely use of sched_info_on()

[Yi Wang]

sched_info_on() is called with unlikely hint, however, the test
is to be a constant(1) on which compiler will do nothing when
make defconfig, so remove the hint.

Also, fix a lack of {}.

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
---
v2: remove the hint rather than replace with likely, and fix a
coding style.

 kernel/sched/stats.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index aa0de24..ba683fe 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -157,9 +157,10 @@ static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
 {
 	unsigned long long now = rq_clock(rq), delta = 0;
 
-	if (unlikely(sched_info_on()))
+	if (sched_info_on()) {
 		if (t->sched_info.last_queued)
 			delta = now - t->sched_info.last_queued;
+	}
 	sched_info_reset_dequeued(t);
 	t->sched_info.run_delay += delta;
 
@@ -192,7 +193,7 @@ static void sched_info_arrive(struct rq *rq, struct task_struct *t)
  */
 static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
 {
-	if (unlikely(sched_info_on())) {
+	if (sched_info_on()) {
 		if (!t->sched_info.last_queued)
 			t->sched_info.last_queued = rq_clock(rq);
 	}
@@ -239,7 +240,7 @@ static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
 static inline void
 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
 {
-	if (unlikely(sched_info_on()))
+	if (sched_info_on())
 		__sched_info_switch(rq, prev, next);
 }
 
-- 
1.8.3.1

Re: [PATCH v2] sched: fix unlikely use of sched_info_on()

[Peter Zijlstra]

On Fri, Jul 05, 2019 at 12:35:07PM +0800, Yi Wang wrote:
> sched_info_on() is called with unlikely hint, however, the test
> is to be a constant(1) on which compiler will do nothing when
> make defconfig, so remove the hint.
> 
> Also, fix a lack of {}.
> 
> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>

Thanks!

[tip:sched/core] sched/stats: Fix unlikely() use of sched_info_on()

[tip-bot for Yi Wang]

Commit-ID:  65d74e91694e1afac40c96fb64a9ef120757729e
Gitweb:     https://git.kernel.org/tip/65d74e91694e1afac40c96fb64a9ef120757729e
Author:     Yi Wang <wang.yi59@zte.com.cn>
AuthorDate: Fri, 5 Jul 2019 12:35:07 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 25 Jul 2019 15:51:55 +0200

sched/stats: Fix unlikely() use of sched_info_on()

sched_info_on() is called with unlikely hint, however, the test
is to be a constant(1) on which compiler will do nothing when
make defconfig, so remove the hint.

Also, fix a lack of {}.

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: up2wing@gmail.com
Cc: wang.liang82@zte.com.cn
Cc: xue.zhihong@zte.com.cn
Link: https://lkml.kernel.org/r/1562301307-43002-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/stats.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index aa0de240fb41..ba683fe81a6e 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -157,9 +157,10 @@ static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
 {
 	unsigned long long now = rq_clock(rq), delta = 0;
 
-	if (unlikely(sched_info_on()))
+	if (sched_info_on()) {
 		if (t->sched_info.last_queued)
 			delta = now - t->sched_info.last_queued;
+	}
 	sched_info_reset_dequeued(t);
 	t->sched_info.run_delay += delta;
 
@@ -192,7 +193,7 @@ static void sched_info_arrive(struct rq *rq, struct task_struct *t)
  */
 static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
 {
-	if (unlikely(sched_info_on())) {
+	if (sched_info_on()) {
 		if (!t->sched_info.last_queued)
 			t->sched_info.last_queued = rq_clock(rq);
 	}
@@ -239,7 +240,7 @@ __sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct
 static inline void
 sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
 {
-	if (unlikely(sched_info_on()))
+	if (sched_info_on())
 		__sched_info_switch(rq, prev, next);
 }