[PATCH] sched/fair: code clean up for __sched_period()

[PATCH] sched/fair: code clean up for __sched_period()

[Boqun Feng]

Since commit: 4bf0b77158 ("sched: remove do_div() from
__sched_slice()"), the logic of __sched_period() can be implemented as a
single if-else without any local variable, so this patch cleans it up
with an if-else statement, which expresses the function's logic
straightforwardly.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
 kernel/sched/fair.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4b6e5f6..341a51f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -616,15 +616,10 @@ static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
  */
 static u64 __sched_period(unsigned long nr_running)
 {
-	u64 period = sysctl_sched_latency;
-	unsigned long nr_latency = sched_nr_latency;
-
-	if (unlikely(nr_running > nr_latency)) {
-		period = sysctl_sched_min_granularity;
-		period *= nr_running;
-	}
-
-	return period;
+	if (unlikely(nr_running > sched_nr_latency))
+		return nr_running * sysctl_sched_min_granularity;
+	else
+		return sysctl_sched_latency;
 }
 
 /*
-- 
2.4.5

Re: [PATCH] sched/fair: code clean up for __sched_period()

[Boqun Feng]

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Ping. Any idea on this one?

On Thu, Jul 02, 2015 at 10:25:52PM +0800, Boqun Feng wrote:
> Since commit: 4bf0b77158 ("sched: remove do_div() from
> __sched_slice()"), the logic of __sched_period() can be implemented as a
> single if-else without any local variable, so this patch cleans it up
> with an if-else statement, which expresses the function's logic
> straightforwardly.
> 
> Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
<...>

Thanks,
Boqun

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Re: [PATCH] sched/fair: code clean up for __sched_period()

[Peter Zijlstra]

On Mon, Jul 06, 2015 at 08:41:26PM +0800, Boqun Feng wrote:
> Ping. Any idea on this one?

I think I queued this one.

Re: [PATCH] sched/fair: code clean up for __sched_period()

[Ingo Molnar]

* Peter Zijlstra <peterz@infradead.org> wrote:

> On Mon, Jul 06, 2015 at 08:41:26PM +0800, Boqun Feng wrote:
> > Ping. Any idea on this one?
> 
> I think I queued this one.

Yeah, and I applied it from you earlier today - it's still being a tested, will 
push it out later today.

Thanks,

	Ingo

Re: [PATCH] sched/fair: code clean up for __sched_period()

[Boqun Feng]

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Hi Ingo,

On Mon, Jul 06, 2015 at 02:53:50PM +0200, Ingo Molnar wrote:
> 
> * Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > On Mon, Jul 06, 2015 at 08:41:26PM +0800, Boqun Feng wrote:
> > > Ping. Any idea on this one?
> > 
> > I think I queued this one.
> 
> Yeah, and I applied it from you earlier today - it's still being a tested, will 
> push it out later today.
> 

Clearly, I'm not very familiar with the patch processing flow for
scheduler.. sorry about that. Much clear now, Thank you!

Regards,
Boqun

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Re: [PATCH] sched/fair: code clean up for __sched_period()

[Boqun Feng]

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Hi Peter,

On Mon, Jul 06, 2015 at 02:49:59PM +0200, Peter Zijlstra wrote:
> On Mon, Jul 06, 2015 at 08:41:26PM +0800, Boqun Feng wrote:
> > Ping. Any idea on this one?
> 
> I think I queued this one.

Sorry, I only had looked up in the "tip" tree.. just found it on your
tree. Thank you! 

Regards,
Boqun

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[tip:sched/core] sched/fair: Clean up the __sched_period() code

[tip-bot for Boqun Feng]

Commit-ID:  42d1c60e15ff89150a3b3537fec579f8a8f36a8a
Gitweb:     http://git.kernel.org/tip/42d1c60e15ff89150a3b3537fec579f8a8f36a8a
Author:     Boqun Feng <boqun.feng@gmail.com>
AuthorDate: Thu, 2 Jul 2015 22:25:52 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 6 Jul 2015 15:29:56 +0200

sched/fair: Clean up the __sched_period() code

Since commit:

  4bf0b77158 ("sched: remove do_div() from __sched_slice()")

... the logic of __sched_period() can be implemented as a single if-else
without any local variables, so this patch cleans it up with an if-else
statement, which expresses the function's logic straightforwardly.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435847152-29543-1-git-send-email-boqun.feng@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a53a610..03ea05b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -616,15 +616,10 @@ static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
  */
 static u64 __sched_period(unsigned long nr_running)
 {
-	u64 period = sysctl_sched_latency;
-	unsigned long nr_latency = sched_nr_latency;
-
-	if (unlikely(nr_running > nr_latency)) {
-		period = sysctl_sched_min_granularity;
-		period *= nr_running;
-	}
-
-	return period;
+	if (unlikely(nr_running > sched_nr_latency))
+		return nr_running * sysctl_sched_min_granularity;
+	else
+		return sysctl_sched_latency;
 }
 
 /*

[tip:sched/core] sched/fair: Clean up the __sched_period() code

[tip-bot for Boqun Feng]

Commit-ID:  8e2b0bf397279878babcb39b021edcafe7c945eb
Gitweb:     http://git.kernel.org/tip/8e2b0bf397279878babcb39b021edcafe7c945eb
Author:     Boqun Feng <boqun.feng@gmail.com>
AuthorDate: Thu, 2 Jul 2015 22:25:52 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 7 Jul 2015 08:46:10 +0200

sched/fair: Clean up the __sched_period() code

Since commit:

  4bf0b77158 ("sched: remove do_div() from __sched_slice()")

... the logic of __sched_period() can be implemented as a single if-else
without any local variables, so this patch cleans it up with an if-else
statement, which expresses the function's logic straightforwardly.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435847152-29543-1-git-send-email-boqun.feng@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a53a610..03ea05b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -616,15 +616,10 @@ static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
  */
 static u64 __sched_period(unsigned long nr_running)
 {
-	u64 period = sysctl_sched_latency;
-	unsigned long nr_latency = sched_nr_latency;
-
-	if (unlikely(nr_running > nr_latency)) {
-		period = sysctl_sched_min_granularity;
-		period *= nr_running;
-	}
-
-	return period;
+	if (unlikely(nr_running > sched_nr_latency))
+		return nr_running * sysctl_sched_min_granularity;
+	else
+		return sysctl_sched_latency;
 }
 
 /*