Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933163AbXAZLNW (ORCPT ); Fri, 26 Jan 2007 06:13:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933174AbXAZLNW (ORCPT ); Fri, 26 Jan 2007 06:13:22 -0500 Received: from smtp.osdl.org ([65.172.181.24]:56194 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933163AbXAZLNV (ORCPT ); Fri, 26 Jan 2007 06:13:21 -0500 Date: Fri, 26 Jan 2007 03:13:00 -0800 From: Andrew Morton To: Christoph Lameter Cc: Nick Piggin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] Track mlock()ed pages Message-Id: <20070126031300.59f75b06.akpm@osdl.org> In-Reply-To: References: <45B9A00C.4040701@yahoo.com.au> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1181 Lines: 36 On Thu, 25 Jan 2007 22:36:17 -0800 (PST) Christoph Lameter wrote: > On Fri, 26 Jan 2007, Nick Piggin wrote: > > > Christoph Lameter wrote: > > > Add NR_MLOCK > > > > > > Track mlocked pages via a ZVC Why? > > I think it is not quite right. You are tracking the number of ptes > > that point to mlocked pages, which can be >= the actual number of pages. > > Mlocked pages are not inherited. I would expect sharing to be very rare. > > > Also, page_add_anon_rmap still needs to be balanced with page_remove_rmap. > > Hmmm.... > > > I can't think of an easy way to do this without per-page state. ie. > > another page flag. > > Thats what I am trying to avoid. You could perhaps go for a walk across all the other vmas which presently map this page. If any of them have VM_LOCKED, don't increment the counter. Similar on removal: only decrement the counter when the final mlocked VMA is dropping the pte. - 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/