linux-kernel - [PATCH] sched/rt: Remove redundant nr_cpus

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Message-Id: <1380914693-24634-1-git-send-email-shawn.bohrer@gmail.com>
Date:	Fri,  4 Oct 2013 14:24:53 -0500
From:	Shawn Bohrer <shawn.bohrer@...il.com>
To:	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>
Cc:	linux-kernel@...r.kernel.org, Steven Rostedt <rostedt@...dmis.org>,
	Mike Galbraith <mgalbraith@...e.de>, tomk@...advisors.com,
	Shawn Bohrer <sbohrer@...advisors.com>
Subject: [PATCH] sched/rt: Remove redundant nr_cpus_allowed test

From: Shawn Bohrer <sbohrer@...advisors.com>

In 76854c7e8f3f4172fef091e78d88b3b751463ac6 "sched: Use
rt.nr_cpus_allowed to recover select_task_rq() cycles" an optimization
was added to select_task_rq_rt() that immediately returns when
p->nr_cpus_allowed == 1 at the beginning of the function.  This makes
the latter p->nr_cpus_allowed > 1 check redundant and can be removed.

Signed-off-by: Shawn Bohrer <sbohrer@...advisors.com>
---
 kernel/sched/rt.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 01970c8..ceebfba 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1213,8 +1213,7 @@ select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
 	 */
 	if (curr && unlikely(rt_task(curr)) &&
 	    (curr->nr_cpus_allowed < 2 ||
-	     curr->prio <= p->prio) &&
-	    (p->nr_cpus_allowed > 1)) {
+	     curr->prio <= p->prio)) {
 		int target = find_lowest_rq(p);
 
 		if (target != -1)
-- 
1.8.1.4

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