Em Tue, 4 Dec 2007 17:00:05 +0100
Ingo Molnar <mingo@elte.hu> escreveu:
|
| * Linus Torvalds <torvalds@linux-foundation.org> wrote:
|
| >
| >
| > On Tue, 4 Dec 2007, Luiz Fernando N. Capitulino wrote:
| > >
| > > sched_rr_get_interval(1, NULL);
| >
| > Looks like we have a zero "cfs_rq->load.weight".
| >
| > Ingo? Both sched_slice() and __sched_slice() do a divide by the
| > runqueue weight, and at least dequeue_task_fair() explicitly checks
| > for that being zero, so clearly zero is a possible value. Hmm?
|
| yeah, i can reproduce this crash too.
|
| The problem is on SMP: if sched_rr_get_interval() gets a task from an
| otherwise idle runqueue, then rq->load.weight is 0. Normally
| sched_slice() is only used on a busy runqueue. So the correct fixup site
| is not in sched_slice() but in sys_sched_rr_get_interval() - i'm working
| on the right fix, i hope to be able to send a pull request in a few
| minutes.
Ingo, I can reproduce this w/o SMP support as well.
(Also, the backtrace I sent was reproduced on a UP machine with a
SMP kernel).
--
Luiz Fernando N. Capitulino
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