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From: Peter Zijlstra <peterz@infradead.org>
To: Wang Xingchao <xingchao.wang@intel.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu,
	yong.zhang0@gmail.com, Paul Turner <pjt@google.com>
Subject: Re: [PATCH] cfs: remove unused 'if' condition checking
Date: Fri, 16 Sep 2011 10:38:32 +0200	[thread overview]
Message-ID: <1316162312.10174.2.camel@twins> (raw)
In-Reply-To: <1316194552-12019-1-git-send-email-xingchao.wang@intel.com>

Thanks, queued it as:

---
Subject: sched: Remove redundant test in check_preempt_tick()
From: Wang Xingchao <xingchao.wang@intel.com>
Date: Fri, 16 Sep 2011 13:35:52 -0400

The caller already checks for nr_running > 1, therefore we don't have
to do so again.

Signed-off-by: Wang Xingchao <xingchao.wang@intel.com>
Reviewed-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1316194552-12019-1-git-send-email-xingchao.wang@intel.com
---
 kernel/sched_fair.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 1ca2cd4..fef0bfd 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1106,6 +1106,8 @@ static void
 check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 {
 	unsigned long ideal_runtime, delta_exec;
+	struct sched_entity *se;
+	s64 delta;
 
 	ideal_runtime = sched_slice(cfs_rq, curr);
 	delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
@@ -1127,16 +1129,14 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 	if (delta_exec < sysctl_sched_min_granularity)
 		return;
 
-	if (cfs_rq->nr_running > 1) {
-		struct sched_entity *se = __pick_first_entity(cfs_rq);
-		s64 delta = curr->vruntime - se->vruntime;
+	se = __pick_first_entity(cfs_rq);
+	delta = curr->vruntime - se->vruntime;
 
-		if (delta < 0)
-			return;
+	if (delta < 0)
+		return;
 
-		if (delta > ideal_runtime)
-			resched_task(rq_of(cfs_rq)->curr);
-	}
+	if (delta > ideal_runtime)
+		resched_task(rq_of(cfs_rq)->curr);
 }
 
 static void
-- 
1.7.1



  parent reply	other threads:[~2011-09-16  8:38 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-16 17:35 [PATCH] cfs: remove unused 'if' condition checking Wang Xingchao
2011-09-16  5:54 ` Yong Zhang
2011-09-16  7:39 ` Paul Turner
2011-09-16  7:41 ` Paul Turner
2011-09-16  8:17   ` Yong Zhang
2011-09-16  8:28     ` Paul Turner
2011-09-16 20:36       ` xingchao
2011-09-16  8:38 ` Peter Zijlstra [this message]
2011-09-16 20:40   ` xingchao

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