From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756449AbYBSNeW (ORCPT ); Tue, 19 Feb 2008 08:34:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752290AbYBSNeN (ORCPT ); Tue, 19 Feb 2008 08:34:13 -0500 Received: from host36-195-149-62.serverdedicati.aruba.it ([62.149.195.36]:42770 "EHLO mx.cpushare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752103AbYBSNeM (ORCPT ); Tue, 19 Feb 2008 08:34:12 -0500 Date: Tue, 19 Feb 2008 14:34:05 +0100 From: Andrea Arcangeli To: Nick Piggin Cc: Christoph Lameter , akpm@linux-foundation.org, Robin Holt , Avi Kivity , Izik Eidus , kvm-devel@lists.sourceforge.net, Peter Zijlstra , general@lists.openfabrics.org, Steve Wise , Roland Dreier , Kanoj Sarcar , steiner@sgi.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, daniel.blueman@quadrics.com Subject: Re: [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges Message-ID: <20080219133405.GH7128@v2.random> References: <20080215064859.384203497@sgi.com> <20080215064932.620773824@sgi.com> <200802191954.14874.nickpiggin@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200802191954.14874.nickpiggin@yahoo.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 19, 2008 at 07:54:14PM +1100, Nick Piggin wrote: > As far as sleeping inside callbacks goes... I think there are big > problems with the patch (the sleeping patch and the external rmap > patch). I don't think it is workable in its current state. Either > we have to make some big changes to the core VM, or we have to turn > some locks into sleeping locks to do it properly AFAIKS. Neither > one is good. Agreed. The thing is quite simple, the moment we support xpmem the complexity in the mmu notifier patch start and there are hacks, duplicated functionality through the same xpmem callbacks etc... GRU can already be 100% supported (infact simpler and safer) with my patch. > But anyway, I don't really think the two approaches (Andrea's > notifiers vs sleeping/xrmap) should be tangled up too much. I > think Andrea's can possibly be quite unintrusive and useful very > soon. Yes, that's why I kept maintaining my patch and I posted the last revision to Andrew. I use pte/tlb locking of the core VM, it's unintrusive and obviously safe. Furthermore it can be extended with Christoph's stuff in a 100% backwards compatible fashion later if needed. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: Re: [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges Date: Tue, 19 Feb 2008 14:34:05 +0100 Message-ID: <20080219133405.GH7128@v2.random> References: <20080215064859.384203497@sgi.com> <20080215064932.620773824@sgi.com> <200802191954.14874.nickpiggin@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: steiner@sgi.com, Peter Zijlstra , linux-mm@kvack.org, Kanoj Sarcar , Roland Dreier , Steve Wise , linux-kernel@vger.kernel.org, Avi Kivity , kvm-devel@lists.sourceforge.net, daniel.blueman@quadrics.com, Robin Holt , general@lists.openfabrics.org, akpm@linux-foundation.org, Christoph Lameter To: Nick Piggin Return-path: Content-Disposition: inline In-Reply-To: <200802191954.14874.nickpiggin@yahoo.com.au> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org On Tue, Feb 19, 2008 at 07:54:14PM +1100, Nick Piggin wrote: > As far as sleeping inside callbacks goes... I think there are big > problems with the patch (the sleeping patch and the external rmap > patch). I don't think it is workable in its current state. Either > we have to make some big changes to the core VM, or we have to turn > some locks into sleeping locks to do it properly AFAIKS. Neither > one is good. Agreed. The thing is quite simple, the moment we support xpmem the complexity in the mmu notifier patch start and there are hacks, duplicated functionality through the same xpmem callbacks etc... GRU can already be 100% supported (infact simpler and safer) with my patch. > But anyway, I don't really think the two approaches (Andrea's > notifiers vs sleeping/xrmap) should be tangled up too much. I > think Andrea's can possibly be quite unintrusive and useful very > soon. Yes, that's why I kept maintaining my patch and I posted the last revision to Andrew. I use pte/tlb locking of the core VM, it's unintrusive and obviously safe. Furthermore it can be extended with Christoph's stuff in a 100% backwards compatible fashion later if needed. ------------------------------------------------------------------------- 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/ From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 19 Feb 2008 14:34:05 +0100 From: Andrea Arcangeli Subject: Re: [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges Message-ID: <20080219133405.GH7128@v2.random> References: <20080215064859.384203497@sgi.com> <20080215064932.620773824@sgi.com> <200802191954.14874.nickpiggin@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200802191954.14874.nickpiggin@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Christoph Lameter , akpm@linux-foundation.org, Robin Holt , Avi Kivity , Izik Eidus , kvm-devel@lists.sourceforge.net, Peter Zijlstra , general@lists.openfabrics.org, Steve Wise , Roland Dreier , Kanoj Sarcar , steiner@sgi.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, daniel.blueman@quadrics.com List-ID: On Tue, Feb 19, 2008 at 07:54:14PM +1100, Nick Piggin wrote: > As far as sleeping inside callbacks goes... I think there are big > problems with the patch (the sleeping patch and the external rmap > patch). I don't think it is workable in its current state. Either > we have to make some big changes to the core VM, or we have to turn > some locks into sleeping locks to do it properly AFAIKS. Neither > one is good. Agreed. The thing is quite simple, the moment we support xpmem the complexity in the mmu notifier patch start and there are hacks, duplicated functionality through the same xpmem callbacks etc... GRU can already be 100% supported (infact simpler and safer) with my patch. > But anyway, I don't really think the two approaches (Andrea's > notifiers vs sleeping/xrmap) should be tangled up too much. I > think Andrea's can possibly be quite unintrusive and useful very > soon. Yes, that's why I kept maintaining my patch and I posted the last revision to Andrew. I use pte/tlb locking of the core VM, it's unintrusive and obviously safe. Furthermore it can be extended with Christoph's stuff in a 100% backwards compatible fashion later if needed. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org