From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [patch 3/4] KVM: introduce irq_lock, use it to protect ioapic
Date: Mon, 25 May 2009 08:11:14 -0300
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Cc: kvm@vger.kernel.org, Gregory Haskins <gregory.haskins@gmail.com>
To: Avi Kivity <avi@redhat.com>
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On Sun, May 24, 2009 at 05:10:07PM +0300, Avi Kivity wrote:
> Marcelo Tosatti wrote:
>> Subject says it all.
>>   
>
> I hate those changelogs.  I guess Subject never reviews code.
>
> You might put some evidence that we're suffering from contention here  
> (I'm very willing to believe it, but hard evidence is better).

Don't have any evidence yet, the main purpose of the split is to fix the
deadlock.

But, with the data we have so far, slots_lock and kvm->lock will cause
significant cache bouncing on EPT hardware (with measurements on shadow
mmu_lock is #1 offender).