From: James Bottomley Date: Mon, 29 Oct 2007 20:18:11 +0000 (+0100) Subject: sched: fix incorrect assumption that cpu 0 exists X-Git-Tag: v2.6.24-rc2~96^2~4 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7bae49d498de87f0da0c20c67adaa278eac84566;p=linux-2.6 sched: fix incorrect assumption that cpu 0 exists This patch: commit 9b5b77512dce239fa168183fa71896712232e95a Author: Srivatsa Vaddagiri 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: James Bottomley Signed-off-by: Ingo Molnar --- diff --git a/kernel/sched.c b/kernel/sched.c index 74dbb4020c..235952b100 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7041,7 +7041,7 @@ static void free_sched_group(struct rcu_head *rhp) /* Destroy runqueue etc associated with a task group */ void sched_destroy_group(struct task_group *tg) { - struct cfs_rq *cfs_rq; + struct cfs_rq *cfs_rq = NULL; int i; for_each_possible_cpu(i) { @@ -7049,7 +7049,7 @@ void sched_destroy_group(struct task_group *tg) 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 */ call_rcu(&cfs_rq->rcu, free_sched_group);