Commit 7bae49d4 authored by James Bottomley's avatar James Bottomley Committed by Ingo Molnar

sched: fix incorrect assumption that cpu 0 exists

This patch:

commit 9b5b7751
Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Date:   Mon Oct 15 17:00:09 2007 +0200

    sched: clean up code under CONFIG_FAIR_GROUP_SCHED

Introduced an assumption of the existence of CPU0 via this line

cfs_rq = tg->cfs_rq[0];

If you have no CPU0, that will be NULL.  The fix seems to be just to
take whatever cfs_rq queue comes out of the for_each_possible_cpu()
loop, since they're all equally good for the destruction operation.
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 73a2bcb0
...@@ -7041,7 +7041,7 @@ static void free_sched_group(struct rcu_head *rhp) ...@@ -7041,7 +7041,7 @@ static void free_sched_group(struct rcu_head *rhp)
/* Destroy runqueue etc associated with a task group */ /* Destroy runqueue etc associated with a task group */
void sched_destroy_group(struct task_group *tg) void sched_destroy_group(struct task_group *tg)
{ {
struct cfs_rq *cfs_rq; struct cfs_rq *cfs_rq = NULL;
int i; int i;
for_each_possible_cpu(i) { for_each_possible_cpu(i) {
...@@ -7049,7 +7049,7 @@ void sched_destroy_group(struct task_group *tg) ...@@ -7049,7 +7049,7 @@ void sched_destroy_group(struct task_group *tg)
list_del_rcu(&cfs_rq->leaf_cfs_rq_list); list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
} }
cfs_rq = tg->cfs_rq[0]; BUG_ON(!cfs_rq);
/* wait for possible concurrent references to cfs_rqs complete */ /* wait for possible concurrent references to cfs_rqs complete */
call_rcu(&cfs_rq->rcu, free_sched_group); call_rcu(&cfs_rq->rcu, free_sched_group);
......
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