From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 09/13] KVM: MMU: get expected spte out of mmu-lock Date: Mon, 09 Apr 2012 16:21:59 +0300 Message-ID: <4F82E277.7030508@redhat.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Xiao Guangrong , Xiao Guangrong , Marcelo Tosatti , LKML , KVM To: Takuya Yoshikawa Return-path: In-Reply-To: <20120409221630.8c94f31ef68d4a89941a3413@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.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