Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757683Ab0GDObK (ORCPT ); Sun, 4 Jul 2010 10:31:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45903 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757395Ab0GDObH (ORCPT ); Sun, 4 Jul 2010 10:31:07 -0400 Message-ID: <4C309B23.9060808@redhat.com> Date: Sun, 04 Jul 2010 17:30:59 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-3.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Xiao Guangrong CC: Marcelo Tosatti , LKML , KVM list Subject: Re: [PATCH v4 5/6] KVM: MMU: combine guest pte read between walk and pte prefetch References: <4C2C9DC0.8050607@cn.fujitsu.com> <4C2C9E6C.2040803@cn.fujitsu.com> <20100702170303.GC25969@amt.cnet> <4C2F117C.2000006@cn.fujitsu.com> <4C2F2835.5060508@redhat.com> <4C2F2A0C.90704@cn.fujitsu.com> <4C2F2C5B.9020503@redhat.com> <4C2F2DBB.50904@cn.fujitsu.com> <4C2F30BD.7050702@redhat.com> <4C2F31D9.5010104@redhat.com> <4C2F3527.3020307@cn.fujitsu.com> In-Reply-To: <4C2F3527.3020307@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1290 Lines: 38 On 07/03/2010 04:03 PM, Xiao Guangrong wrote: > > Avi Kivity wrote: > > >>> >>> Well, in the description, it looked like everything was using small >>> pages (in kvm, level=1 means PTE level, we need to change this one >>> day). Please describe again and say exactly when the guest or host >>> uses large pages. >>> >>> >>> >> Oh, I see what you mean. >> >> Regarding the patch, is it possible just to move the check before, >> instead of adding the 'check' variable? >> >> > Umm, if we move the check before the judgment, it'll check every level, > actually, only the opened mapping and the laster level need checked, so > for the performance reason, maybe it's better to keep two check-point. > What exactly are the conditions when you want to check? Perhaps we do need to check every level. A write to a PDE (or higher level) will clear the corresponding spte, but a fault immediately afterwards can re-establish the spte to point to the new page. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/