[patch] [sched] fork-fix 2.5.3-pre5

[Ingo Molnar]

the patch below fixes a fork() bug introduced by the new scheduler. If the
parent process schedules away and gets rebalanced to another CPU then
wake_up_forked_process() does runqueue manipulation incorrectly.

the crash was first reported by Robert Love, it happened with the
preemption patches applied. Later the crash was reproduced on the 2.4 +
O(1) kernel as well, using Cerberus.

	Ingo

--- linux/kernel/sched.c.orig	Fri Jan 25 10:44:18 2002
+++ linux/kernel/sched.c	Fri Jan 25 12:06:36 2002
@@ -275,6 +293,7 @@
 		p->prio = effective_prio(p);
 	}
 	spin_lock_irq(&rq->lock);
+	p->cpu = smp_processor_id();
 	activate_task(p, rq);
 	spin_unlock_irq(&rq->lock);
 }