Re: [git pull] scheduler updates for v2.6.24

Ingo Molnar
2007-10-15T18:53:37Z

* Andrew Morton <akpm@linux-foundation.org> wrote:

> On Mon, 15 Oct 2007 16:17:23 +0200
> Ingo Molnar <mingo@elte.hu> wrote:
>
> > Linus, please pull the latest scheduler git tree from:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched.git
>
> Did Paul Jackson's crash get fixed?

yes - that crash was a showstopper that was holding up the pull request
for 2 days. Paul bisected it down to the culprit and the fix was to do
this in wake_up_new_task():

- if (!p->sched_class->task_new || !current->se.on_rq) {
+ if (!p->sched_class->task_new || !current->se.on_rq || !rq->cfs.curr) {

(during early bootup the cfs_rq has no curr pointer yet.) It's not clear
why this race did not trigger earlier. (and the two checks can probably
be consolidated into a single "!rq->cfs.curr" condition.)

Ingo