On Mon, Apr 15, 2019 at 11:39:57PM +0000, Dexuan Cui wrote: > > From: Peter Zijlstra <[email protected]> > > Sent: Monday, April 15, 2019 5:21 AM > > To: Dexuan Cui <[email protected]> > > > > On Fri, Apr 12, 2019 at 11:53:57PM +0000, Dexuan Cui wrote: > > > If smp_call_function_single() is calling the function for itself, it's > > > safe > > > to run with irqs_disabled() == true. > > > > > > I hit the warning because I'm in the below path in the .suspend callback > > > of > > > a "syscore_ops" to support hibernation for a VM running on Hyper-V: > > > > > > hv_synic_cleanup() -> > > > clockevents_unbind_device() -> > > > clockevents_unbind() -> > > > smp_call_function_single(). > > > > > > When the .suspend callback runs, only CPU0 is online and irqs_disabled() > > > is > > > true. > > > > Pray tell, how well do you think mutex_lock() works with interrupts > > disabled? > > Good point. I realized generally speaking this patch makes no sense, so let me > try the solution proposed by Vitaly, i.e. fix clockevents_unbind() instead.
That's still not the problem. You're calling clockevents_unbind_device() with IRQs disabled, that's not correct. It doesn't matter what clockevents_unbind() does thereafter. You simply cannot do any of this with IRQs disabled, end of story.
