From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767270AbXDTVDj (ORCPT ); Fri, 20 Apr 2007 17:03:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767271AbXDTVDj (ORCPT ); Fri, 20 Apr 2007 17:03:39 -0400 Received: from smtp1.linux-foundation.org ([65.172.181.25]:51488 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767270AbXDTVDi (ORCPT ); Fri, 20 Apr 2007 17:03:38 -0400 Date: Fri, 20 Apr 2007 14:03:16 -0700 From: Andrew Morton To: Rik van Riel Cc: Jakub Jelinek , linux-kernel , linux-mm Subject: Re: [PATCH] lazy freeing of memory through MADV_FREE 2/2 Message-Id: <20070420140316.e0155e7d.akpm@linux-foundation.org> In-Reply-To: <4627DBF0.1080303@redhat.com> References: <46247427.6000902@redhat.com> <4627DBF0.1080303@redhat.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-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 On Thu, 19 Apr 2007 17:15:28 -0400 Rik van Riel wrote: > Restore MADV_DONTNEED to its original Linux behaviour. This is still > not the same behaviour as POSIX, but applications may be depending on > the Linux behaviour already. Besides, glibc catches POSIX_MADV_DONTNEED > and makes sure nothing is done... OK, we need to flesh this out a lot please. People often get confused about what our MADV_DONTNEED behaviour is. I regularly forget, then look at the code, then get it wrong. That's for mainline, let alone older kernels whose behaviour is gawd-knows-what. So... For the changelog (and the manpage) could we please have a full description of the 2.6.21 behaviour and the 2.6.21-post-rik behaviour (and the 2.4 behaviour, if it differs at all)? Also some code comments to demystify all of this once and for all? Thanks.