[PATCH] [4/6] scheduler: Refactor normalize_rt_tasks

Andi Kleen
2007-10-07T21:01:23Z

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

Signed-off-by: Andi Kleen <ak@suse.de>

Index: linux-2.6-sched-devel/kernel/sched.c
===================================================================
--- linux-2.6-sched-devel.orig/kernel/sched.c
+++ linux-2.6-sched-devel/kernel/sched.c
@@ -74,6 +74,12 @@ unsigned long long __attribute__((weak))
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 ],
@@ -6534,12 +6540,25 @@ 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) {
@@ -6563,26 +6582,10 @@ 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);