From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267655AbUBTBLS (ORCPT ); Thu, 19 Feb 2004 20:11:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267611AbUBTBHd (ORCPT ); Thu, 19 Feb 2004 20:07:33 -0500 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:16138 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id S267626AbUBTBEo (ORCPT ); Thu, 19 Feb 2004 20:04:44 -0500 Message-ID: <40355D0D.3010800@transmeta.com> Date: Thu, 19 Feb 2004 17:04:13 -0800 From: "H. Peter Anvin" Organization: Transmeta Corporation User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20031030 X-Accept-Language: en, sv MIME-Version: 1.0 To: Andries.Brouwer@cwi.nl CC: linux-kernel@vger.kernel.org Subject: Re: kernel too big References: In-Reply-To: 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 Andries.Brouwer@cwi.nl wrote: > In 2.5.61 hpa changed > > - /* 0x28000*16 = 2.5 MB, conservative estimate for the current maximum */ > - if (sys_size > (is_big_kernel ? 0x28000 : DEF_SYSSIZE)) > + /* 0x40000*16 = 4.0 MB, reasonable estimate for the current maximum */ > + if (sys_size > (is_big_kernel ? 0x40000 : DEF_SYSSIZE)) > die("System is too big. ..."); > > (with comment "bootsect removal"). > > Today I find for a 2.6.3 machine that it boots with 2994 kB and > crashes at boot time with 3005 kB. > > Thus, it looks like this "reasonable estimate" is too optimistic. > > If I understand correctly, the real requirement is that > _end must stay below 8MB (unless the initial page tables > in head.S are made larger). A crash occurs with _end = c07fcf8c. > > Maybe these "conservative" or "reasonable" estimates should be > replaced by a text on _end? > What we should do is to actually look at the limit that matters. Also, if the limit really is around 3 MB compressed we probably need to extend it to 16 MB uncompressed; we're a little too close for comfort.