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From: Gregory Haskins <ghaskins@novell.com>
To: Steven Rostedt <rostedt@goodmis.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: RT <linux-rt-users@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
	LKML <linux-kernel@vger.kernel.org>,
	Gregory Haskins <ghaskins@novell.com>
Subject: [PATCH 6/9] RT: Clean up some of the push-rt logic
Date: Wed, 17 Oct 2007 14:50:57 -0400	[thread overview]
Message-ID: <20071017185057.11272.72369.stgit@novell1.haskins.net> (raw)
In-Reply-To: <20071017184745.11272.10024.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 67034aa..d604484 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1519,20 +1519,21 @@ 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())
@@ -1541,7 +1542,6 @@ 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;
 			}
 
@@ -1549,7 +1549,6 @@ 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;
 			}
 		}
 
@@ -1564,7 +1563,7 @@ 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;
@@ -1595,7 +1594,6 @@ 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);
 
@@ -1603,13 +1601,11 @@ 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:[~2007-10-17 19:07 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-17 18:50 [PATCH 0/9] RT: RT-Overload/Sched enhancements v4 Gregory Haskins
2007-10-17 18:50 ` [PATCH 1/9] RT: push-rt Gregory Haskins
2007-10-17 18:50 ` [PATCH 2/9] RT: Add a per-cpu rt_overload indication Gregory Haskins
2007-10-17 18:50 ` [PATCH 3/9] RT: Wrap the RQ notion of priority to make it conditional Gregory Haskins
2007-10-17 18:50 ` [PATCH 4/9] RT: Initialize the priority value Gregory Haskins
2007-10-17 18:50 ` [PATCH 5/9] RT: Maintain the highest RQ priority Gregory Haskins
2007-10-17 18:50 ` Gregory Haskins [this message]
2007-10-17 18:51 ` [PATCH 7/9] RT: Add support for low-priority wake-up to push_rt feature Gregory Haskins
2007-10-17 18:51 ` [PATCH 8/9] RT: Fixes for push-rt patch Gregory Haskins
2007-10-17 18:51 ` [PATCH 9/9] RT: Only dirty a cacheline if the priority is actually changing Gregory Haskins
2007-10-20  2:48   ` Roel Kluin
2007-10-20  7:54     ` Steven Rostedt
2007-10-20 10:44     ` Gregory Haskins

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