Re: [PATCH v3 6/6] freezer,sched: Rewrite core freezer logic

[Christian Borntraeger]

Am 26.09.22 um 15:37 schrieb Peter Zijlstra:
> On Mon, Sep 26, 2022 at 03:23:10PM +0200, Christian Borntraeger wrote:
> > Am 26.09.22 um 14:55 schrieb Peter Zijlstra:
> >
> > > Could you please test with something like the below on? I can boot that
> > > with KVM, but obviously I didn't suffer any weirdness to begin with :/
> > >
> > > ---
> > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> > > index 4e6a6417211f..ef9ccfc3a8c0 100644
> > > --- a/kernel/sched/core.c
> > > +++ b/kernel/sched/core.c
> > > @@ -4051,6 +4051,8 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
> > >    	unsigned long flags;
> > >    	int cpu, success = 0;
> > > +	WARN_ON_ONCE(state & TASK_FREEZABLE);
> > > +
> > >    	preempt_disable();
> > >    	if (p == current) {
> > >    		/*
> >
> > Does not seem to trigger.
>
> Moo -- quite the puzzle this :/ I'll go stare at it more then.

In the end this is about the end of the sshd process (shutting it down).
I can also trigger the problem by sending a SIGTERM so its not about
the shutdown itself.
Pofiling the guest I see scheduler functions like sched_clock, pick_next_entity,
update_min_vruntime and so on with 100% system time.