Re: [PATCH] little schedule() cleanup: use cached current value

[Oleg Nesterov <oleg@tv-sign.ru>]

Ingo Molnar wrote:

> nack. We switch the kernel stack in switch_to() so 'next' here
> is the old task we switched to before we went off the CPU.

yes, sorry. here is corrected patch.

schedule() can use prev instead of get_current().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

--- 2.6.10-rc1/kernel/sched.c~	2004-11-09 18:57:45.000000000 +0300
+++ 2.6.10-rc1/kernel/sched.c	2004-11-09 19:16:22.798486040 +0300
@@ -2508,7 +2508,7 @@ need_resched:
 	 * The idle thread is not allowed to schedule!
 	 * Remove this check after it has been exercised a bit.
 	 */
-	if (unlikely(current == rq->idle) && current->state != TASK_RUNNING) {
+	if (unlikely(prev == rq->idle) && prev->state != TASK_RUNNING) {
 		printk(KERN_ERR "bad: scheduling from the idle thread!\n");
 		dump_stack();
 	}
@@ -2531,8 +2531,8 @@ need_resched:
 
 	spin_lock_irq(&rq->lock);
 
-	if (unlikely(current->flags & PF_DEAD))
-		current->state = EXIT_DEAD;
+	if (unlikely(prev->flags & PF_DEAD))
+		prev->state = EXIT_DEAD;
 	/*
 	 * if entering off of a kernel preemption go straight
 	 * to picking the next task.