From mboxrd@z Thu Jan  1 00:00:00 1970
From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Subject: Re: [PATCH 7/7] KVM: MMU: don't walk every parent pages while mark
 unsync
Date: Fri, 11 Jun 2010 21:43:20 +0800
Message-ID: <4C123D78.5040705@cn.fujitsu.com>
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Cc: Marcelo Tosatti <mtosatti@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	KVM list <kvm@vger.kernel.org>
To: Avi Kivity <avi@redhat.com>
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Xiao Guangrong wrote:
> While we mark the parent's unsync_child_bitmap, if the parent is already
> unsynced, it no need walk it's parent, it can reduce some unnecessary
> workload
> 

Hi Avi, Marcelo,

About two months ago, i have sent this optimization, it just a little performance
improved (~0.5%) at that time, now, we allow more page become unsync, this path is
called higher frequency, during my test, kernelbench show the performance improved
~2%, so, i think we may apply it now :-)