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Diffstat (limited to 'kernel/sched_rt.c')
-rw-r--r--kernel/sched_rt.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 72c81322fb9a..52d88f193afc 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -303,7 +303,7 @@ static int find_lowest_cpus(struct task_struct *task, cpumask_t *lowest_mask)
int cpu;
cpumask_t *valid_mask = &__get_cpu_var(valid_cpu_mask);
int lowest_prio = -1;
- int ret = 0;
+ int count = 0;
cpus_clear(*lowest_mask);
cpus_and(*valid_mask, cpu_online_map, task->cpus_allowed);
@@ -316,7 +316,7 @@ static int find_lowest_cpus(struct task_struct *task, cpumask_t *lowest_mask)
/* We look for lowest RT prio or non-rt CPU */
if (rq->rt.highest_prio >= MAX_RT_PRIO) {
- if (ret)
+ if (count)
cpus_clear(*lowest_mask);
cpu_set(rq->cpu, *lowest_mask);
return 1;
@@ -328,14 +328,17 @@ static int find_lowest_cpus(struct task_struct *task, cpumask_t *lowest_mask)
if (rq->rt.highest_prio > lowest_prio) {
/* new low - clear old data */
lowest_prio = rq->rt.highest_prio;
- cpus_clear(*lowest_mask);
+ if (count) {
+ cpus_clear(*lowest_mask);
+ count = 0;
+ }
}
cpu_set(rq->cpu, *lowest_mask);
- ret = 1;
+ count++;
}
}
- return ret;
+ return count;
}
static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
@@ -359,9 +362,17 @@ static int find_lowest_rq(struct task_struct *task)
cpumask_t *lowest_mask = &__get_cpu_var(local_cpu_mask);
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
+ int count = find_lowest_cpus(task, lowest_mask);
- if (!find_lowest_cpus(task, lowest_mask))
- return -1;
+ if (!count)
+ return -1; /* No targets found */
+
+ /*
+ * There is no sense in performing an optimal search if only one
+ * target is found.
+ */
+ if (count == 1)
+ return first_cpu(*lowest_mask);
/*
* At this point we have built a mask of cpus representing the