From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: Re: [patch 0/4] [RFC] MMU Notifiers V1 Date: Mon, 28 Jan 2008 20:40:05 +0100 Message-ID: <20080128194005.GE7233@v2.random> References: <20080125055606.102986685@sgi.com> <20080125114229.GA7454@v2.random> <479DFE7F.9030305@qumranet.com> <20080128172521.GC7233@v2.random> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Nick Piggin , Peter Zijlstra , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Benjamin Herrenschmidt , steiner-sJ/iWh9BUns@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Avi Kivity , kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, daniel.blueman-xqY44rlHlBpWk0Htik3J/w@public.gmane.org, Robin Holt , Hugh Dickins To: Christoph Lameter Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Mon, Jan 28, 2008 at 11:04:43AM -0800, Christoph Lameter wrote: > On Mon, 28 Jan 2008, Andrea Arcangeli wrote: > > > So I'd like to know what can we do to help to merge the 4 patches from > > Christoph in mainline, I'd appreciate comments on them so we can help > > to address any outstanding issue! > > There are still some pending issues (RCU troubles). I will post V2 today. With regard to the synchronize_rcu troubles they also be left to the notifier-user to solve. Certainly having the synchronize_rcu like in your last incremental patches in _release, will require less complications (kvm pins the mm so I suppose we could batch the call_rcu externally too). But _release is not a fast-path for KVM usage so your V2 is sure ok (and simpler to deal with) too. For registration synchronize_rcu is the only way, if the notifiers have to fire synchronously before mmu_notifier_register returns but that also can be left up to the caller if required (for example KVM doesn't need that). Otherwise there could be two mmu_notifier_register and mmu_notifier_register_rcu where the latter calls synchronize_rcu before returning. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/