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>

1 files changed, 23 insertions, 20 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index db88b5655aca..2c6295b395a9 100644
--- 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);