From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH] mmu notifiers #v2 Date: Wed, 16 Jan 2008 07:18:53 +1100 Message-ID: <1200428333.6755.0.camel@pasglop> References: <20080113162418.GE8736@v2.random> <20080115124449.GK30812@v2.random> Reply-To: benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Andrew Morton , Nick Piggin , kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, steiner-sJ/iWh9BUns@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Avi Kivity , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, daniel.blueman-xqY44rlHlBpWk0Htik3J/w@public.gmane.org, holt-sJ/iWh9BUns@public.gmane.org, Hugh Dickins , Christoph Lameter To: Andrea Arcangeli Return-path: In-Reply-To: <20080115124449.GK30812-lysg2Xt5kKMAvxtiuMwx3w@public.gmane.org> 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 Tue, 2008-01-15 at 13:44 +0100, Andrea Arcangeli wrote: > On Mon, Jan 14, 2008 at 12:02:42PM -0800, Christoph Lameter wrote: > > Hmmm... In most of the callsites we hold a writelock on mmap_sem right? > > Not in all, like Marcelo pointed out in kvm-devel, so the lowlevel > locking can't relay on the VM locks. > > About your request to schedule in the mmu notifier methods this is not > feasible right now, the notifier is often called with the pte > spinlocks held. I wonder if you can simply post/queue an event like a > softirq/pdflush. Do you have cases where it's -not- called with the PTE lock held ? Ben. ------------------------------------------------------------------------- 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/