Re: [lkp] [fs] df4c0e36f1: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]

Dave Hansen
2015-11-02T20:07:59Z

On 11/02/2015 11:34 AM, Andrey Ryabinin wrote:
>>> >>
>>> >> [ 1.159450] augmented rbtree testing -> 23675 cycles
>>> >> [ 1.864996]
>>> >> It took less than a second, meanwhile in your case it didn't finish in
>>> >> 22 seconds.
>>> >>
>>> >> This makes me think that your host is overloaded and the problem is on
>>> >> your side.
>> >
>> > It's probably just a matter of putting some cond_resched()s in the test
>> > code.
> Yes, but is it worthwhile? It's very likely that lockup will just
> trigger in another place.

I'm guessing that the lockup here was because the tests were running for
too long. If we cond_resched() in there often enough, the kernel won't
detect a softlockup at all. It won't shift somewhere else.