Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754028Ab0F3BCL (ORCPT ); Tue, 29 Jun 2010 21:02:11 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:52911 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752677Ab0F3BCJ (ORCPT ); Tue, 29 Jun 2010 21:02:09 -0400 Message-ID: <4C2A96AE.6020103@cn.fujitsu.com> Date: Wed, 30 Jun 2010 08:58:22 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Marcelo Tosatti CC: Avi Kivity , LKML , KVM list Subject: Re: [PATCH v2 8/10] KVM: MMU: prefetch ptes when intercepted guest #PF References: <4C2498EC.2010006@cn.fujitsu.com> <4C249BEA.1030908@cn.fujitsu.com> <20100628130431.GA6209@amt.cnet> <4C29A9CC.2080508@cn.fujitsu.com> <20100629114446.GB26369@amt.cnet> In-Reply-To: <20100629114446.GB26369@amt.cnet> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 770 Lines: 21 Marcelo Tosatti wrote: >>> Also prefetch should be disabled for EPT, due to lack of accessed bit. >>> >> But we call mmu_set_spte() with speculative == false, it not touch the accessed bit. > > There is no accessed bit on EPT. So the aging code (kvm_age_rmapp) > considers any present translation as accessed. There is no way to > distinguish between actually accessed translations and prefetched (but > unused) ones. > You are right, i'll disable the prefetch for EPT in the next version, thanks for you point it out. -- 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/