Re: [PATCH 1/4] KVM: Add APIs for unlocked TLB flush

[Avi Kivity <avi@redhat.com>]

On 05/08/2012 04:55 AM, Marcelo Tosatti wrote:
> > > Yes, so, we can change kvm_mark_tlb_dirty to:
> > >
> > > +static inline void kvm_mark_tlb_dirty(struct kvm *kvm)
> > > +{
> > > +	/*
> > > +	 * Make any changes to the page tables visible to remote flushers.
> > > +	 */
> > > +	smb_mb();
> > > +	kvm->tlb_state.dirtied_count++;
> > > +}
> > >
> > 
> > Yes.  We'll have to change it again if we ever dirty sptes outside the
> > lock, but that's okay.
>
> Please don't. There are readers outside mmu_lock, so it should be
> atomic.

Why does it need to be atomic?  All it needs is to be properly barriered
(provided by spin_unlock(mmu_lock)).

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