[PATCH 3/8] RT: Break out the search function
From: Gregory Haskins <hidden>
Date: 2007-11-06 00:17:18
Subsystem:
the rest · Maintainer:
Linus Torvalds
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 <redacted> --- 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)) { /*