Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758185AbYBIB1T (ORCPT ); Fri, 8 Feb 2008 20:27:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754920AbYBIB1J (ORCPT ); Fri, 8 Feb 2008 20:27:09 -0500 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:42254 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752310AbYBIB1H (ORCPT ); Fri, 8 Feb 2008 20:27:07 -0500 Date: Fri, 8 Feb 2008 17:27:03 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Andrea Arcangeli cc: Roland Dreier , a.p.zijlstra@chello.nl, izike@qumranet.com, steiner@sgi.com, linux-kernel@vger.kernel.org, avi@qumranet.com, linux-mm@kvack.org, daniel.blueman@quadrics.com, Robin Holt , general@lists.openfabrics.org, Andrew Morton , kvm-devel@lists.sourceforge.net, Rik van Riel Subject: Re: [ofa-general] Re: [patch 0/6] MMU Notifiers V6 In-Reply-To: <20080209012446.GB7051@v2.random> Message-ID: References: <20080208233636.GG26564@sgi.com> <20080208234302.GH26564@sgi.com> <20080208155641.2258ad2c.akpm@linux-foundation.org> <20080209012446.GB7051@v2.random> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1070 Lines: 22 On Sat, 9 Feb 2008, Andrea Arcangeli wrote: > > Hmmmm.. that means we need something that actually pins pages for good so > > that the VM can avoid reclaiming it and so that page migration can avoid > > trying to migrate them. Something like yet another page flag. > > What's wrong with pinning with the page count like now? Dumb adapters > would simply not register themself in the mmu notifier list no? Pages will still be on the LRU and cycle through rmap again and again. If page migration is used on those pages then the code may make repeated attempt to migrate the page thinking that the page count must at some point drop. I do not think that the page count was intended to be used to pin pages permanently. If we had a marker on such pages then we could take them off the LRU and not try to migrate them. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/