Re: [PATCH 00/11] another rt group sched update

[Peter Zijlstra <peterz@infradead.org>]

On Mon, 2008-01-07 at 11:51 +0100, Peter Zijlstra wrote:

>  - I occasionally see a weird lockup on iterating the task_groups list
>    on smp machines. - I failed to see anything wrong, but hey, this
>    stack of used brown paper bags is steadily growing.

D'oh

---

Don't add a task_group to the task_groups list for each cpu, there is
only a single task_group.


Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---

Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -7175,6 +7175,10 @@ void __init sched_init(void)
 	init_defrootdomain();
 #endif
 
+#ifdef CONFIG_FAIR_GROUP_SCHED
+	list_add(&init_task_group.list, &task_groups);
+#endif
+
 	for_each_possible_cpu(i) {
 		struct rq *rq;
 
@@ -7201,8 +7205,6 @@ void __init sched_init(void)
 		init_tg_rt_entry(rq, &init_task_group,
 				&per_cpu(init_rt_rq, i),
 				&per_cpu(init_sched_rt_entity, i), i, 1);
-
-		list_add(&init_task_group.list, &task_groups);
 #endif
 
 		for (j = 0; j < CPU_LOAD_IDX_MAX; j++)