Re: kvm: RCU warning in async pf
From: Avi Kivity
Date: Thu Apr 05 2012 - 12:11:37 EST
On 04/04/2012 03:30 PM, Gleb Natapov wrote:
> On Tue, Apr 03, 2012 at 01:52:26PM +0300, Gleb Natapov wrote:
> > On Mon, Apr 02, 2012 at 08:54:32PM -0400, Sasha Levin wrote:
> > > Hi all,
> > >
> > > I got the spew at the bottom of the mail in a KVM guest using the KVM tools and running trinity.
> > >
> > > I'm not quite sure how default_idle managed to trigger a pagefault, so that part looks odd to me.
> > >
> > This is not regular page fault. This is async page fault that tells the
> > guest that a page, previously swapped out by hypervisor, is now swapped
> > back in and it can happen while vcpu is idle. The code does not leave
> > idle state properly though. We probably need to call rcu_irq_enter()
> > there. Will look into it.
> >
>
> The patch below solves it for me:
>
> "Page ready" async PF can kick vcpu out of idle state much like IRQ.
> We need to tell RCU about this.
>
>
Applied it, thanks.
--
error compiling committee.c: too many arguments to function
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