Messages in this thread |  | | Date | Mon, 10 Nov 2014 10:48:28 -0500 | From | Sasha Levin <> | Subject | Re: [PATCH v4] sched/numa: fix unsafe get_task_struct() in task_numa_assign() |
| |
On 11/10/2014 05:03 AM, Peter Zijlstra wrote: > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -1268,6 +1268,13 @@ static void task_numa_compare(struct tas > raw_spin_unlock_irq(&dst_rq->lock); > > /* > + * Because we have preemption enabled we can get migrated around and > + * end try selecting ourselves (current == env->p) as a swap candidate. > + */ > + if (cur == env->p) > + goto unlock;
This is too late though, because currently the lockup happens couple of lines above that at:
raw_spin_lock_irq(&dst_rq->lock); <=== here cur = dst_rq->curr;
Which got me a bit stuck trying to use your old patch since we can't access '->curr' without locking dst_rq, but locking dst_rq is causing a lockup.
Thanks, Sasha
|  |