Re: [tip:sched/core] sched/core: Add debugging code to catch missing update_rq_clock() calls
From: Michael Ellerman
Date: Tue Jan 31 2017 - 03:36:15 EST
Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> writes:
> On Tue, 31 Jan, at 08:24:53AM, Michael Ellerman wrote:
>> I'm hitting this on multiple powerpc systems:
>> [ 38.339126] rq->clock_update_flags < RQCF_ACT_SKIP
>> [ 38.339134] ------------[ cut here ]------------
>> [ 38.339142] WARNING: CPU: 2 PID: 1 at kernel/sched/sched.h:804 detach_task_cfs_rq+0xa0c/0xd10
>> I assume I should be worried?
> Thanks for the report. No need to worry, the bug has existed for a
> while, this patch just turns on the warning ;-)
> The following commit queued up in tip/sched/core should fix your
> issues (assuming you see the same callstack on all your powerpc
Looks like that commit is in today's linux-next, so hopefully I won't
see any oopses in my boot tests overnight. If I do I'll let you know.