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From: Gregory Haskins <ghaskins@novell.com>
To: linux-rt-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Gregory Haskins <ghaskins@novell.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Dmitry Adamushko <dmitry.adamushko@gmail.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@elte.hu>, Darren Hart <dvhltc@us.ibm.com>
Subject: [PATCH 07/13] RT: Clean up some of the push-rt logic
Date: Tue, 23 Oct 2007 12:50:59 -0400	[thread overview]
Message-ID: <20071023165059.5536.51340.stgit@novell1.haskins.net> (raw)
In-Reply-To: <20071023164156.5536.95573.stgit@novell1.haskins.net>

Get rid of the superfluous dst_cpu, and move the cpu_mask inside the search
function.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
---

 kernel/sched.c |   18 +++++++-----------
 1 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index c17e2e4..0600062 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1517,20 +1517,21 @@ static int double_lock_balance(struct rq *this_rq, struct rq *busiest);
 #define RT_PUSH_MAX_TRIES 3
 
 /* Will lock the rq it finds */
-static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask,
-				      struct task_struct *task,
+static struct rq *find_lock_lowest_rq(struct task_struct *task,
 				      struct rq *this_rq)
 {
 	struct rq *lowest_rq = NULL;
-	int dst_cpu = -1;
 	int cpu;
 	int tries;
+	cpumask_t cpu_mask;
+
+	cpus_and(cpu_mask, cpu_online_map, task->cpus_allowed);
 
 	for (tries = 0; tries < RT_PUSH_MAX_TRIES; tries++) {
 		/*
 		 * Scan each rq for the lowest prio.
 		 */
-		for_each_cpu_mask(cpu, *cpu_mask) {
+		for_each_cpu_mask(cpu, cpu_mask) {
 			struct rq *rq = &per_cpu(runqueues, cpu);
 
 			if (cpu == smp_processor_id())
@@ -1539,7 +1540,6 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask,
 			/* We look for lowest RT prio or non-rt CPU */
 			if (rq->highest_prio >= MAX_RT_PRIO) {
 				lowest_rq = rq;
-				dst_cpu = cpu;
 				break;
 			}
 
@@ -1547,7 +1547,6 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask,
 			if (rq->highest_prio > task->prio &&
 			    (!lowest_rq || rq->highest_prio < lowest_rq->highest_prio)) {
 				lowest_rq = rq;
-				dst_cpu = cpu;
 			}
 		}
 
@@ -1562,7 +1561,7 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask,
 			 * migrated already or had its affinity changed.
 			 */
 			if (unlikely(task_rq(task) != this_rq ||
-				     !cpu_isset(dst_cpu, task->cpus_allowed))) {
+				     !cpu_isset(lowest_rq->cpu, task->cpus_allowed))) {
 				spin_unlock(&lowest_rq->lock);
 				lowest_rq = NULL;
 				break;
@@ -1593,7 +1592,6 @@ static int push_rt_task(struct rq *this_rq)
 	struct rq *lowest_rq;
 	int dst_cpu;
 	int ret = 0;
-	cpumask_t cpu_mask;
 
 	assert_spin_locked(&this_rq->lock);
 
@@ -1601,13 +1599,11 @@ static int push_rt_task(struct rq *this_rq)
 	if (!next_task)
 		return 0;
 
-	cpus_and(cpu_mask, cpu_online_map, next_task->cpus_allowed);
-
 	/* We might release this_rq lock */
 	get_task_struct(next_task);
 
 	/* find_lock_lowest_rq locks the rq if found */
-	lowest_rq = find_lock_lowest_rq(&cpu_mask, next_task, this_rq);
+	lowest_rq = find_lock_lowest_rq(next_task, this_rq);
 	if (!lowest_rq)
 		goto out;
 


  parent reply	other threads:[~2007-10-23 17:07 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-23 16:50 [PATCH 00/13] Balance RT tasks v5 Gregory Haskins
2007-10-23 16:50 ` [PATCH 01/13] RT: push-rt Gregory Haskins
2007-10-23 16:50 ` [PATCH 02/13] RT: Condense the next-task search into one function Gregory Haskins
2007-10-23 16:50 ` [PATCH 03/13] RT: Add a per-cpu rt_overload indication Gregory Haskins
2007-10-23 16:50 ` [PATCH 04/13] RT: Wrap the RQ notion of priority to make it conditional Gregory Haskins
2007-10-23 16:50 ` [PATCH 05/13] RT: Initialize the priority value Gregory Haskins
2007-10-23 16:50 ` [PATCH 06/13] RT: Maintain the highest RQ priority Gregory Haskins
2007-10-23 16:50 ` Gregory Haskins [this message]
2007-10-23 16:51 ` [PATCH 08/13] RT: Add support for low-priority wake-up to push_rt feature Gregory Haskins
2007-10-23 16:51 ` [PATCH 09/13] RT: Only dirty a cacheline if the priority is actually changing Gregory Haskins
2007-10-23 16:51 ` [PATCH 10/13] RT: Fixes for push-rt patch Gregory Haskins
2007-10-23 16:51 ` [PATCH 11/13] RT: Condense NORMAL and IDLE priorities Gregory Haskins
2007-10-23 16:51 ` [PATCH 12/13] RT: CPU priority management Gregory Haskins
2007-10-23 16:51 ` [PATCH 13/13] RT: Cache cpus_allowed weight for optimizing migration Gregory Haskins
2007-10-24  0:19   ` Ingo Oeser
2007-10-24  3:20     ` Gregory Haskins

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