From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992892AbXDDM1Y (ORCPT ); Wed, 4 Apr 2007 08:27:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992895AbXDDM1X (ORCPT ); Wed, 4 Apr 2007 08:27:23 -0400 Received: from ns2.suse.de ([195.135.220.15]:37361 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992892AbXDDM1W (ORCPT ); Wed, 4 Apr 2007 08:27:22 -0400 Date: Wed, 4 Apr 2007 14:27:01 +0200 From: Andrea Arcangeli To: Nick Piggin Cc: Hugh Dickins , Andrew Morton , Linus Torvalds , Linux Memory Management List , tee@sgi.com, holt@sgi.com, Linux Kernel Mailing List Subject: Re: [rfc] no ZERO_PAGE? Message-ID: <20070404122701.GB19587@v2.random> References: <20070329075805.GA6852@wotan.suse.de> <20070330024048.GG19407@wotan.suse.de> <20070404033726.GE18507@wotan.suse.de> <20070404102407.GA529@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070404102407.GA529@wotan.suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 04, 2007 at 12:24:07PM +0200, Nick Piggin wrote: > But for a potential mainline merge, maybe starting with a CONFIG > option is a good idea -- defaulting to off, and we could start by > turning it on just in -rc kernels for a few releases, to get a bit > more confidence? The only reason to do that is if there are many stupid apps pretending to get meaningful information from pages that cannot contain any information. The zero page in the anon page fault has been there forever so... Anyway I also like this approach as I immediately suggested it after reading about the zero page scalability patches ;).