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Message-ID: <1334582840.28150.43.camel@twins>
Subject: Re: kvm: RCU warning in async pf
From: Peter Zijlstra <peterz@infradead.org>
To: Gleb Natapov <gleb@redhat.com>
Cc: Sasha Levin <levinsasha928@gmail.com>, Avi Kivity <avi@redhat.com>,
        Marcelo Tosatti <mtosatti@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        kvm <kvm@vger.kernel.org>, linux-kernel <linux-kernel@vger.kernel.org>,
        Dave Jones <davej@redhat.com>
Date: Mon, 16 Apr 2012 15:27:20 +0200
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On Mon, 2012-04-16 at 15:18 +0200, Peter Zijlstra wrote:
> On Mon, 2012-04-16 at 16:08 +0300, Gleb Natapov wrote:
> > On Mon, Apr 16, 2012 at 03:05:48PM +0200, Peter Zijlstra wrote:
> > > On Mon, 2012-04-16 at 15:58 +0300, Gleb Natapov wrote:
> > > > -               rcu_irq_enter();
> > > > +               irq_enter();
> > > >                 exit_idle(); 
> > > 
> > > Do we really need the exit_idle()? I can't remember other interrupt
> > > handlers doing that.
> > They do. That's where I got the idea.
> 
> Some do.. some don't.. /me goes have a look what this exit_idle nonsense
> is all about. Looks to be something broken.

Yeah, its broken and the whole implementation is crap anyway. There's
only one user (drivers/idle/i7300_idle.c) so it likely doesn't matter
(much) anyway.

Thomas, can we rip that stuff out? or do we have to like actually fix
it?