sched: cleanup: refactor normalize_rt_tasks

Replace a particularly ugly ifdef with an inline and a new macro.
Also split up the function to be easier to read.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched.c b/kernel/sched.c
index db88b56..2c6295b 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -75,6 +75,12 @@ unsigned long long __attribute__((weak)) sched_clock(void)
        return (unsigned long long)jiffies * (1000000000 / HZ);
 }
 
+#ifdef CONFIG_SMP
+#define is_migration_thread(p, rq) ((p) == (rq)->migration_thread)
+#else
+#define is_migration_thread(p, rq) 0
+#endif
+
 /*
  * Convert user-nice values [ -20 ... 0 ... 19 ]
  * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
@@ -6532,12 +6538,25 @@ EXPORT_SYMBOL(__might_sleep);
 #endif
 
 #ifdef CONFIG_MAGIC_SYSRQ
+static void normalize_task(struct rq *rq, struct task_struct *p)
+{
+       int on_rq;
+       update_rq_clock(rq);
+       on_rq = p->se.on_rq;
+       if (on_rq)
+               deactivate_task(rq, p, 0);
+       __setscheduler(rq, p, SCHED_NORMAL, 0);
+       if (on_rq) {
+               activate_task(rq, p, 0);
+               resched_task(rq->curr);
+       }
+}
+
 void normalize_rt_tasks(void)
 {
        struct task_struct *g, *p;
        unsigned long flags;
        struct rq *rq;
-       int on_rq;
 
        read_lock_irq(&tasklist_lock);
        do_each_thread(g, p) {
@@ -6561,26 +6580,10 @@ void normalize_rt_tasks(void)
 
                spin_lock_irqsave(&p->pi_lock, flags);
                rq = __task_rq_lock(p);
-#ifdef CONFIG_SMP
-               /*
-                * Do not touch the migration thread:
-                */
-               if (p == rq->migration_thread)
-                       goto out_unlock;
-#endif
 
-               update_rq_clock(rq);
-               on_rq = p->se.on_rq;
-               if (on_rq)
-                       deactivate_task(rq, p, 0);
-               __setscheduler(rq, p, SCHED_NORMAL, 0);
-               if (on_rq) {
-                       activate_task(rq, p, 0);
-                       resched_task(rq->curr);
-               }
-#ifdef CONFIG_SMP
- out_unlock:
-#endif
+               if (!is_migration_thread(p, rq))
+                       normalize_task(rq, p);
+
                __task_rq_unlock(rq);
                spin_unlock_irqrestore(&p->pi_lock, flags);
        } while_each_thread(g, p);