Re: sched: Unexpected reschedule of offline CPU#2!

From: Henning Schild
Date: Tue Jul 27 2021 - 04:01:13 EST


Was this ever resolved and if so can someone please point me to the
patches? I started digging a bit but could not yet find how that
continued.

I am seeing similar or maybe the same problem on 4.19.192 with the
ipipe patch from the xenomai project applied.

regards,
Henning

Am Sat, 17 Aug 2019 22:21:48 +0200
schrieb Thomas Gleixner <tglx@xxxxxxxxxxxxx>:

> On Fri, 16 Aug 2019, Guenter Roeck wrote:
> > On Fri, Aug 16, 2019 at 12:22:22PM +0200, Thomas Gleixner wrote:
> > > diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> > > index 75fea0d48c0e..625627b1457c 100644
> > > --- a/arch/x86/kernel/process.c
> > > +++ b/arch/x86/kernel/process.c
> > > @@ -601,6 +601,7 @@ void stop_this_cpu(void *dummy)
> > > /*
> > > * Remove this CPU:
> > > */
> > > + set_cpu_active(smp_processor_id(), false);
> > > set_cpu_online(smp_processor_id(), false);
> > > disable_local_APIC();
> > > mcheck_cpu_clear(this_cpu_ptr(&cpu_info));
> > >
> > No luck. The problem is still seen with this patch applied on top of
> > the mainline kernel (commit a69e90512d9def6).
>
> Yeah, was a bit too naive ....
>
> We actually need to do the full cpuhotplug dance for a regular
> reboot. In the panic case, there is nothing we can do about. I'll
> have a look tomorrow.
>
> Thanks,
>
> tglx