On Thu, Jan 21, 2021 at 03:57:03PM +0100, Peter Zijlstra wrote: > On Mon, Jan 11, 2021 at 05:10:47PM +0000, [email protected] wrote: > > From: Vincent Donnefort <[email protected]> > > > > After the AP brought itself down to CPUHP_TEARDOWN_CPU, the BP will finish > > the job. The steps left are as followed: > > > > +--------------------+ > > | CPUHP_TEARDOWN_CPU | -> If fails state is CPUHP_TEARDOWN_CPU > > +--------------------+ > > | ATOMIC STATES | -> Cannot Fail > > +--------------------+ > > | CPUHP_BRINGUP_CPU | -> Cannot fail > > +--------------------+ > > | ... | > > | ... | -> Can fail and rollback > > These are the PREPARE/DEAD states, right? It would be _really_ daft for > a DEAD notifier to fail. But yeah, I suppose that if it does, it will > indeed end up in CPUHP_AP_ONLINE_IDLE. > > Do we want to WARN when a DEAD notifier fails? > >
Indeed, I couldn't find a dead callback which can return an error. So I suppose we could go for another strategy here, that would be to not allow failure for the dead states (i.e states < BRINGUP_CPU when hotunplug). In that case, the fail interface should probably disallow selecting those states and a WARN here would be good. -- Vincent
