From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751006AbXDUSHw (ORCPT ); Sat, 21 Apr 2007 14:07:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751130AbXDUSHw (ORCPT ); Sat, 21 Apr 2007 14:07:52 -0400 Received: from mx2.redhat.com ([66.187.237.31]:53477 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751006AbXDUSHv (ORCPT ); Sat, 21 Apr 2007 14:07:51 -0400 Message-ID: <462A52BF.7000801@redhat.com> Date: Sat, 21 Apr 2007 14:06:55 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Hugh Dickins CC: Andrew Morton , linux-kernel , linux-mm Subject: Re: [PATCH] lazy freeing of memory through MADV_FREE References: <46247427.6000902@redhat.com> <20070420135715.f6e8e091.akpm@linux-foundation.org> <462932BE.4020005@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hugh Dickins wrote: > On Fri, 20 Apr 2007, Rik van Riel wrote: >> Andrew Morton wrote: >> >>> I do go on about that. But we're adding page flags at about one per >>> year, and when we run out we're screwed - we'll need to grow the >>> pageframe. >> If you want, I can take a look at folding this into the >> ->mapping pointer. I can guarantee you it won't be >> pretty, though :) > > Please don't. If we're going to stuff another pageflag into there, > let it be PageSwapCache the natural partner of PageAnon, rather than > whatever our latest pageflag happens to be. I looked at doing what Andrew wanted, and it did indeed not look like the right thing to do. The locking on page->mapping is the kind of locking we want to avoid during zap_page_range and in the pageout code. I like your suggestion better. -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic.