sched: Use replace normalize_task() with __sched_setscheduler()

Reduce duplicate logic; normalize_task() is a simplified version of
__sched_setscheduler(). Parametrize the difference and collapse.

This reduces the amount of check_class_changed() sites.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: ktkhai@parallels.com
Cc: rostedt@goodmis.org
Cc: juri.lelli@gmail.com
Cc: pang.xunlei@linaro.org
Cc: oleg@redhat.com
Cc: wanpeng.li@linux.intel.com
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/20150611124742.532642391@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fa32bc09dadf7041caf2e8b12b76942d48a4684d..b610ef9e522f03b7d0ff4ccbce22aa8710e205d6 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3438,7 +3438,7 @@ static bool dl_param_changed(struct task_struct *p,
 
 static int __sched_setscheduler(struct task_struct *p,
                                const struct sched_attr *attr,
-                               bool user)
+                               bool user, bool pi)
 {
        int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 :
                      MAX_RT_PRIO - 1 - attr->sched_priority;
@@ -3624,18 +3624,20 @@ change:
        p->sched_reset_on_fork = reset_on_fork;
        oldprio = p->prio;
 
-       /*
-        * Take priority boosted tasks into account. If the new
-        * effective priority is unchanged, we just store the new
-        * normal parameters and do not touch the scheduler class and
-        * the runqueue. This will be done when the task deboost
-        * itself.
-        */
-       new_effective_prio = rt_mutex_get_effective_prio(p, newprio);
-       if (new_effective_prio == oldprio) {
-               __setscheduler_params(p, attr);
-               task_rq_unlock(rq, p, &flags);
-               return 0;
+       if (pi) {
+               /*
+                * Take priority boosted tasks into account. If the new
+                * effective priority is unchanged, we just store the new
+                * normal parameters and do not touch the scheduler class and
+                * the runqueue. This will be done when the task deboost
+                * itself.
+                */
+               new_effective_prio = rt_mutex_get_effective_prio(p, newprio);
+               if (new_effective_prio == oldprio) {
+                       __setscheduler_params(p, attr);
+                       task_rq_unlock(rq, p, &flags);
+                       return 0;
+               }
        }
 
        queued = task_on_rq_queued(p);
@@ -3646,7 +3648,7 @@ change:
                put_prev_task(rq, p);
 
        prev_class = p->sched_class;
-       __setscheduler(rq, p, attr, true);
+       __setscheduler(rq, p, attr, pi);
 
        if (running)
                p->sched_class->set_curr_task(rq);
@@ -3661,7 +3663,8 @@ change:
        check_class_changed(rq, p, prev_class, oldprio);
        task_rq_unlock(rq, p, &flags);
 
-       rt_mutex_adjust_pi(p);
+       if (pi)
+               rt_mutex_adjust_pi(p);
 
        return 0;
 }
@@ -3682,7 +3685,7 @@ static int _sched_setscheduler(struct task_struct *p, int policy,
                attr.sched_policy = policy;
        }
 
-       return __sched_setscheduler(p, &attr, check);
+       return __sched_setscheduler(p, &attr, check, true);
 }
 /**
  * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
@@ -3703,7 +3706,7 @@ EXPORT_SYMBOL_GPL(sched_setscheduler);
 
 int sched_setattr(struct task_struct *p, const struct sched_attr *attr)
 {
-       return __sched_setscheduler(p, attr, true);
+       return __sched_setscheduler(p, attr, true, true);
 }
 EXPORT_SYMBOL_GPL(sched_setattr);
 
@@ -7361,32 +7364,12 @@ EXPORT_SYMBOL(___might_sleep);
 #endif
 
 #ifdef CONFIG_MAGIC_SYSRQ
-static void normalize_task(struct rq *rq, struct task_struct *p)
+void normalize_rt_tasks(void)
 {
-       const struct sched_class *prev_class = p->sched_class;
+       struct task_struct *g, *p;
        struct sched_attr attr = {
                .sched_policy = SCHED_NORMAL,
        };
-       int old_prio = p->prio;
-       int queued;
-
-       queued = task_on_rq_queued(p);
-       if (queued)
-               dequeue_task(rq, p, 0);
-       __setscheduler(rq, p, &attr, false);
-       if (queued) {
-               enqueue_task(rq, p, 0);
-               resched_curr(rq);
-       }
-
-       check_class_changed(rq, p, prev_class, old_prio);
-}
-
-void normalize_rt_tasks(void)
-{
-       struct task_struct *g, *p;
-       unsigned long flags;
-       struct rq *rq;
 
        read_lock(&tasklist_lock);
        for_each_process_thread(g, p) {
@@ -7413,9 +7396,7 @@ void normalize_rt_tasks(void)
                        continue;
                }
 
-               rq = task_rq_lock(p, &flags);
-               normalize_task(rq, p);
-               task_rq_unlock(rq, p, &flags);
+               __sched_setscheduler(p, &attr, false, false);
        }
        read_unlock(&tasklist_lock);
 }