From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Subject: Re: [PATCH] KVM: make kvm_mmu_zap_page() return the number of pages
 it actually freed.
Date: Thu, 06 May 2010 17:25:24 +0800
Message-ID: <4BE28B04.2010305@cn.fujitsu.com>
References: <4BE0C3F5.1010907@cn.fujitsu.com> <4BE286EA.3070206@redhat.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>, kvm@vger.kernel.org
To: Avi Kivity <avi@redhat.com>
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Avi Kivity wrote:
> On 05/05/2010 04:03 AM, Gui Jianfeng wrote:
>> Currently, kvm_mmu_zap_page() returning the number of freed children sp.
>> This might confuse the caller, because caller don't know the actual freed
>> number. Let's make kvm_mmu_zap_page() return the number of pages it
>> actually
>> freed.
>>
>>    
> 
>             if (kvm_mmu_zap_page(kvm, sp))
>                 goto restart;
> 
> Needs to be updated.

Hi Avi,

if kvm_mmu_zap_page() returns 1, we don't know whether the freed sp is the one we passes into
or the child. So here just restart hash walk as long as kvm_mmu_zap_page() returning a positive
number, although sometimes un-needed hash walk will happen. This fix gets code simpler, the
idea comes from Marcelo.

Thanks,
Gui

>