Re: NUMA scheduler broken

[Ingo Molnar]

On Fri, 7 Mar 2003, Rick Lindsley wrote:

> Looks like __activate_task() should call nr_running_inc(rq) rather than
> rq->nr_running++, and the same in wake_up_forked_process().  My guess is
> that the bogus node_nr_running value is causing some really poor
> scheduling decisions to be made on NUMA.  See if that changes your
> result.

indeed. The attached patch (against BK-curr) fixes this.

	Ingo

--- kernel/sched.c.orig	2003-03-07 13:40:53.000000000 +0100
+++ kernel/sched.c	2003-03-07 13:41:19.000000000 +0100
@@ -325,7 +325,7 @@
 static inline void __activate_task(task_t *p, runqueue_t *rq)
 {
 	enqueue_task(p, rq->active);
-	rq->nr_running++;
+	nr_running_inc(rq);
 }
 
 static inline void activate_task(task_t *p, runqueue_t *rq)
@@ -545,7 +545,7 @@
 		list_add_tail(&p->run_list, &current->run_list);
 		p->array = current->array;
 		p->array->nr_active++;
-		rq->nr_running++;
+		nr_running_inc(rq);
 	}
 	task_rq_unlock(rq, &flags);
 }