sched/core: Remove check of p->sched_class

Search all usage of p->sched_class in sched/core.c, no one check it
before use, so it seems that every task must belong to one sched_class.

Signed-off-by: Yao Dongdong <yaodongdong@huawei.com>
[ Moved the early class assignment to make it boot. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1419835303-28958-1-git-send-email-yaodongdong@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 95ac795ab3d32bdcb991ed184aa148340e95b6e5..46a2345f9f45174744dfaeefaea447313245aa66 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4744,7 +4744,7 @@ static struct rq *move_queued_task(struct task_struct *p, int new_cpu)
 
 void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
 {
-       if (p->sched_class && p->sched_class->set_cpus_allowed)
+       if (p->sched_class->set_cpus_allowed)
                p->sched_class->set_cpus_allowed(p, new_mask);
 
        cpumask_copy(&p->cpus_allowed, new_mask);
@@ -7253,6 +7253,11 @@ void __init sched_init(void)
        atomic_inc(&init_mm.mm_count);
        enter_lazy_tlb(&init_mm, current);
 
+       /*
+        * During early bootup we pretend to be a normal task:
+        */
+       current->sched_class = &fair_sched_class;
+
        /*
         * Make us the idle thread. Technically, schedule() should not be
         * called from this thread, however somewhere below it might be,
@@ -7263,11 +7268,6 @@ void __init sched_init(void)
 
        calc_load_update = jiffies + LOAD_FREQ;
 
-       /*
-        * During early bootup we pretend to be a normal task:
-        */
-       current->sched_class = &fair_sched_class;
-
 #ifdef CONFIG_SMP
        zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT);
        /* May be allocated at isolcpus cmdline parse time */