From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH 4/4] KVM MMU: do not intercept invlpg if 'oos_shadow' is disabled Date: Wed, 05 May 2010 20:54:26 +0800 Message-ID: <4BE16A82.4080807@cn.fujitsu.com> References: <4BDA9C37.9070602@cn.fujitsu.com> <4BDA9C86.8080204@cn.fujitsu.com> <4BDA9CD0.6070501@cn.fujitsu.com> <4BDA9D58.6030407@cn.fujitsu.com> <4BDAA94A.8050407@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , KVM list , LKML To: Avi Kivity Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:56307 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754343Ab0EEM5g (ORCPT ); Wed, 5 May 2010 08:57:36 -0400 In-Reply-To: <4BDAA94A.8050407@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 04/30/2010 12:05 PM, Xiao Guangrong wrote: >> If 'oos_shadow' == 0, intercepting invlpg command is really >> unnecessary. >> >> And it's good for us to compare the performance between enable >> 'oos_shadow' >> and disable 'oos_shadow' >> >> @@ -74,8 +74,9 @@ static int dbg = 0; >> module_param(dbg, bool, 0644); >> #endif >> >> -static int oos_shadow = 1; >> +int __read_mostly oos_shadow = 1; >> module_param(oos_shadow, bool, 0644); >> +EXPORT_SYMBOL_GPL(oos_shadow); >> > > Please rename to kvm_oos_shadow to reduce potential for conflict with > other global names. > > But really, this is a debug option, I don't expect people to run with > oos_shadow=0, so there's not much motivation to optimize it. Agreed, but, 'oos_shadow' option is document in Documentation/kernel-parameters.txt, if it's just a debug option, i think we do better not document it. Thanks, Xiao