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. From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <462A52BF.7000801@redhat.com> Date: Sat, 21 Apr 2007 14:06:55 -0400 From: Rik van Riel MIME-Version: 1.0 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: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Andrew Morton , linux-kernel , linux-mm List-ID: 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. -- 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