From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757030Ab2DINWR (ORCPT ); Mon, 9 Apr 2012 09:22:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62020 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751701Ab2DINWP (ORCPT ); Mon, 9 Apr 2012 09:22:15 -0400 Message-ID: <4F82E277.7030508@redhat.com> Date: Mon, 09 Apr 2012 16:21:59 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120316 Thunderbird/11.0 MIME-Version: 1.0 To: Takuya Yoshikawa CC: Xiao Guangrong , Xiao Guangrong , Marcelo Tosatti , LKML , KVM Subject: Re: [PATCH 09/13] KVM: MMU: get expected spte out of mmu-lock References: <4F742951.7080003@linux.vnet.ibm.com> <4F742A97.6030308@linux.vnet.ibm.com> <4F7879E6.8020103@redhat.com> <4F7DE39D.3040207@gmail.com> <4F82D5FF.20202@redhat.com> <20120409221630.8c94f31ef68d4a89941a3413@gmail.com> In-Reply-To: <20120409221630.8c94f31ef68d4a89941a3413@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/2012 04:16 PM, Takuya Yoshikawa wrote: > On Mon, 09 Apr 2012 15:28:47 +0300 > Avi Kivity wrote: > > > Ah, so it's protecting two paths at the same time: rmap.write_protect -> > > fast page fault, and lock(sptep) -> write protect. > > > > The whole thing needs to be documented very carefully in locking.txt, > > otherwise mmu.c will be write-protected to everyone except you. > > Before changing mmu_lock usage, better describe it in locking.txt. > > I guess from mmu.c git history, it is already restricted to a few > people who can describe that. It's getting harder and harder, yes. -- error compiling committee.c: too many arguments to function