Re: [PATCH] KVM: x86: Kick VCPU outside PIC lock again

[Avi Kivity <avi@xxxxxxxxxx>]

On 02/24/2010 11:54 AM, Jan Kiszka wrote:
> Avi Kivity wrote:
>    
> > On 02/24/2010 11:41 AM, Jan Kiszka wrote:
> >      
> > > Thomas Gleixner wrote:
> > >
> > >        
> > > > On Tue, 23 Feb 2010, Jan Kiszka wrote:
> > > >
> > > >
> > > >          
> > > > > Thomas Gleixner wrote:
> > > > >
> > > > >            
> > > > > > The i8254/i8259 locks need to be real spinlocks on preempt-rt. Convert
> > > > > > them to raw_spinlock. No change for !RT kernels.
> > > > > >
> > > > > >              
> > > > > Doesn't fly for -rt anymore: pic_irq_update runs under this raw lock and
> > > > > calls kvm_vcpu_kick which tries to wake_up some thread ->   scheduling
> > > > > while atomic.
> > > > >
> > > > >            
> > > > Hmm, a wakeup itself is fine. Is that code waking a wake queue ?
> > > >
> > > >          
> > > Yes, it's a wake queue.
> > >
> > >        
> > So what's the core issue?  Is the lock_t in the wait_queue a sleeping mutex?
> >      
> Yep.
>    

I see.  Won't we hit the same issue when we call pic functions from 
atomic context during the guest entry sequence?

--
error compiling committee.c: too many arguments to function

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