sched/deadline: Change return value of cpudl_find()

cpudl_find() users are only interested in knowing if suitable CPU(s)
were found or not (and then they look at later_mask to know which).

Change cpudl_find() return type accordingly. Aligns with rt code.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <bristot@redhat.com>
Cc: <juri.lelli@gmail.com>
Cc: <kernel-team@lge.com>
Cc: <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1495504859-10960-3-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index bdf448b..8d9562d 100644 (file)
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -119,29 +119,29 @@ static inline int cpudl_maximum(struct cpudl *cp)
  * @p: the task
  * @later_mask: a mask to fill in with the selected CPUs (or NULL)
  *
- * Returns: int - best CPU (heap maximum if suitable)
+ * Returns: int - CPUs were found
  */
 int cpudl_find(struct cpudl *cp, struct task_struct *p,
               struct cpumask *later_mask)
 {
-       int best_cpu = -1;
        const struct sched_dl_entity *dl_se = &p->dl;
 
        if (later_mask &&
            cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) {
-               best_cpu = cpumask_any(later_mask);
-               goto out;
-       } else if (cpumask_test_cpu(cpudl_maximum(cp), &p->cpus_allowed) &&
-                       dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
-               best_cpu = cpudl_maximum(cp);
-               if (later_mask)
-                       cpumask_set_cpu(best_cpu, later_mask);
-       }
+               return 1;
+       } else {
+               int best_cpu = cpudl_maximum(cp);
+               WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
 
-out:
-       WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
+               if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
+                   dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
+                       if (later_mask)
+                               cpumask_set_cpu(best_cpu, later_mask);
 
-       return best_cpu;
+                       return 1;
+               }
+       }
+       return 0;
 }
 
 /*

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index ac07d7c..d05bd94 100644 (file)
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1594,7 +1594,7 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
         * let's hope p can move out.
         */
        if (rq->curr->nr_cpus_allowed == 1 ||
-           cpudl_find(&rq->rd->cpudl, rq->curr, NULL) == -1)
+           !cpudl_find(&rq->rd->cpudl, rq->curr, NULL))
                return;
 
        /*
@@ -1602,7 +1602,7 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
         * see if it is pushed or pulled somewhere else.
         */
        if (p->nr_cpus_allowed != 1 &&
-           cpudl_find(&rq->rd->cpudl, p, NULL) != -1)
+           cpudl_find(&rq->rd->cpudl, p, NULL))
                return;
 
        resched_curr(rq);
@@ -1811,7 +1811,7 @@ static int find_later_rq(struct task_struct *task)
         * We have to consider system topology and task affinity
         * first, then we can look for a suitable cpu.
         */
-       if (cpudl_find(&task_rq(task)->rd->cpudl, task, later_mask) == -1)
+       if (!cpudl_find(&task_rq(task)->rd->cpudl, task, later_mask))
                return -1;
 
        /*