From: Gregory Haskins <ghaskins@novell.com>
To: rostedt@goodmis.org
Cc: mingo@elte.hu, dvhltc@us.ibm.com, zijlstra@redhat.com,
linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org,
ghaskins@novell.com
Subject: [PATCH 3/8] RT: Break out the search function
Date: Mon, 05 Nov 2007 16:48:48 -0700 [thread overview]
Message-ID: <20071105234847.25451.6571.stgit@lsg> (raw)
In-Reply-To: <20071105234832.25451.55430.stgit@lsg>
Isolate the search logic into a function so that it can be used later
in places other than find_locked_lowest_rq().
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
---
kernel/sched_rt.c | 62 ++++++++++++++++++++++++++++++++---------------------
1 files changed, 37 insertions(+), 25 deletions(-)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index f1fc1b4..fbe7b8a 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -312,43 +312,55 @@ static struct task_struct *pick_next_highest_task_rt(struct rq *rq,
return next;
}
-/* Will lock the rq it finds */
-static struct rq *find_lock_lowest_rq(struct task_struct *task,
- struct rq *rq)
+static int find_lowest_rq(struct task_struct *task)
{
- struct rq *lowest_rq = NULL;
- cpumask_t cpu_mask;
int cpu;
- int tries;
+ cpumask_t cpu_mask;
+ struct rq *lowest_rq = NULL;
cpus_and(cpu_mask, cpu_online_map, task->cpus_allowed);
- for (tries = 0; tries < RT_MAX_TRIES; tries++) {
- /*
- * Scan each rq for the lowest prio.
- */
- for_each_cpu_mask(cpu, cpu_mask) {
- struct rq *curr_rq = &per_cpu(runqueues, cpu);
+ /*
+ * Scan each rq for the lowest prio.
+ */
+ for_each_cpu_mask(cpu, cpu_mask) {
+ struct rq *rq = cpu_rq(cpu);
- if (cpu == rq->cpu)
- continue;
+ if (cpu == rq->cpu)
+ continue;
- /* We look for lowest RT prio or non-rt CPU */
- if (curr_rq->rt.highest_prio >= MAX_RT_PRIO) {
- lowest_rq = curr_rq;
- break;
- }
+ /* We look for lowest RT prio or non-rt CPU */
+ if (rq->rt.highest_prio >= MAX_RT_PRIO) {
+ lowest_rq = rq;
+ break;
+ }
- /* no locking for now */
- if (curr_rq->rt.highest_prio > task->prio &&
- (!lowest_rq || curr_rq->rt.highest_prio > lowest_rq->rt.highest_prio)) {
- lowest_rq = curr_rq;
- }
+ /* no locking for now */
+ if (rq->rt.highest_prio > task->prio &&
+ (!lowest_rq || rq->rt.highest_prio > lowest_rq->rt.highest_prio)) {
+ lowest_rq = rq;
}
+ }
+
+ return lowest_rq ? lowest_rq->cpu : -1;
+}
+
+/* Will lock the rq it finds */
+static struct rq *find_lock_lowest_rq(struct task_struct *task,
+ struct rq *rq)
+{
+ struct rq *lowest_rq = NULL;
+ int cpu;
+ int tries;
+
+ for (tries = 0; tries < RT_MAX_TRIES; tries++) {
+ cpu = find_lowest_rq(task);
- if (!lowest_rq)
+ if (cpu == -1)
break;
+ lowest_rq = cpu_rq(cpu);
+
/* if the prio of this runqueue changed, try again */
if (double_lock_balance(rq, lowest_rq)) {
/*
next prev parent reply other threads:[~2007-11-06 0:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-05 23:48 [PATCH 0/8] RT: scheduler migration/wakeup enhancements Gregory Haskins
2007-11-05 23:48 ` [PATCH 1/8] RT: Consistency cleanup for this_rq usage Gregory Haskins
2007-11-05 23:48 ` [PATCH 2/8] RT: Remove some CFS specific code from the wakeup path of RT tasks Gregory Haskins
2007-11-05 23:48 ` Gregory Haskins [this message]
2007-11-05 23:48 ` [PATCH 4/8] RT: Allow current_cpu to be included in search Gregory Haskins
2007-11-05 23:48 ` [PATCH 5/8] RT: Pre-route RT tasks on wakeup Gregory Haskins
2007-11-05 23:49 ` [PATCH 6/8] RT: Optimize our cpu selection based on topology Gregory Haskins
2007-11-05 23:49 ` [PATCH 7/8] RT: Optimize rebalancing Gregory Haskins
2007-11-05 23:49 ` [PATCH 8/8] RT: Use a 2-d bitmap for searching lowest-pri CPU Gregory Haskins
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