Re: WARNING: CPU: 1 PID: 15 at kernel/sched/sched.h:804 assert_clock_updated.isra.62.part.63+0x25/0x27

From: Ingo Molnar
Date: Tue Jan 31 2017 - 02:29:39 EST



* Mike Galbraith <efault@xxxxxx> wrote:

> On Mon, 2017-01-30 at 11:59 +0000, Matt Fleming wrote:
> > On Sat, 28 Jan, at 08:21:05AM, Mike Galbraith wrote:
> > > Running Steven's hotplug stress script in tip.today. Config is
> > > NOPREEMPT, tune for maximum build time (enterprise default-ish).
> > >
> > > [ 75.268049] x86: Booting SMP configuration:
> > > [ 75.268052] smpboot: Booting Node 0 Processor 1 APIC 0x2
> > > [ 75.279994] smpboot: Booting Node 0 Processor 2 APIC 0x4
> > > [ 75.294617] smpboot: Booting Node 0 Processor 4 APIC 0x1
> > > [ 75.310698] smpboot: Booting Node 0 Processor 5 APIC 0x3
> > > [ 75.359056] smpboot: CPU 3 is now offline
> > > [ 75.415505] smpboot: CPU 4 is now offline
> > > [ 75.479985] smpboot: CPU 5 is now offline
> > > [ 75.550674] ------------[ cut here ]------------
> > > [ 75.550678] WARNING: CPU: 1 PID: 15 at kernel/sched/sched.h:804
> > > assert_clock_updated.isra.62.part.63+0x25/0x27
> > > [ 75.550679] rq->clock_update_flags < RQCF_ACT_SKIP
> >
> > The following patch queued in tip/sched/core should fix this issue:
>
> Weeell, I'll have to take your word for it, as tip g35669bb7fd46 grew
> an early boot brick problem.

That's bad - could you perhaps try to bisect it? All recently queued up patches
that could cause such problems should be readily bisectable.

The bisection might be faster if you first checked whether 5bf728f02218 works - if
it does then the bug is in the patches in WIP.x86/boot or WIP.x86/fpu.

Thanks,

Ingo