Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754261Ab3CKT6R (ORCPT ); Mon, 11 Mar 2013 15:58:17 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45533 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750948Ab3CKT6Q (ORCPT ); Mon, 11 Mar 2013 15:58:16 -0400 Message-ID: <513E36CB.5040908@zytor.com> Date: Mon, 11 Mar 2013 12:55:55 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130219 Thunderbird/17.0.3 MIME-Version: 1.0 To: Vivek Goyal CC: Yinghai Lu , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , WANG Chao , "Eric W. Biederman" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86, kdump: Set crashkernel_low automatically References: <513D52BA.3070206@redhat.com> <1362977817-23297-1-git-send-email-yinghai@kernel.org> <20130311144853.GB8482@redhat.com> <20130311150256.GC8482@redhat.com> <20130311182655.GB12107@redhat.com> <513E2695.3080707@zytor.com> <513E28B8.3000502@zytor.com> <20130311192021.GF12107@redhat.com> In-Reply-To: <20130311192021.GF12107@redhat.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1217 Lines: 31 On 03/11/2013 12:20 PM, Vivek Goyal wrote: > > I find it odd that if a user wants to load a 32bit kernel or use 32bit > entry point then he needs to first reboot the kernel and re-reserve > the memory. > > At installation time, one does not necessarily know what kind of kernel > will be used for crashdump. So reserving as high as possible limits > the choices. > > I would rather prefer that user opt in for higher addresses instead of > these being reserved by default. > Quite frankly the whole design seems to be held together with chewing gum. At the core, the problem is a tight coupling between kexec-tools version, kexec-tools options, and kernel command line options that have to be combined in very ugly ways. Part of the reason is that the kernel isn't actually given the information it needs to do the job required. As far as "if a user wants to load"... why on Earth should that be the default? How could that *not* be an exceptional case? -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/