From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 0/3] Early use of boot service memory Date: Wed, 13 Nov 2013 14:49:42 -0800 Message-ID: <52840206.5020006@zytor.com> References: <1384222558-38527-1-git-send-email-jerry.hoemann@hp.com> <20131113224503.GB25344@anatevka.fc.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131113224503.GB25344-dMAi7lA+vBPDUbYHzcRnttBPR1lH4CV8@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: jerry.hoemann-VXdhtT5mjnY@public.gmane.org Cc: rob-VoJi6FS/r0vR7s880joybQ@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, yinghai-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, penberg-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-efi@vger.kernel.org On 11/13/2013 02:45 PM, jerry.hoemann-VXdhtT5mjnY@public.gmane.org wrote: > > The changes in 3.9 to allow crash kernel to be allocated high helps. > But as you say, the default is still to allocate crash kernel low and > still susceptible to this problem. So, a kdump expert can work around it. > But, not everyone is a kdump expert. > > So, we can work to change the default, or encourage the distros > to always allocate high. Or, we change the call to efi_reserve_boot_services > not apply to all platforms. > > The problems for pre 3.9 based distros is worse as they don't have > ability to allocate crash kernel high. > But they won't have your new option, either, and that is still horribly manual and system-dependent. In other words, allocating the crashkernel high has ALL the advantages, plus a few more, and NONE of the disadvantages. -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751548Ab3KMWuc (ORCPT ); Wed, 13 Nov 2013 17:50:32 -0500 Received: from terminus.zytor.com ([198.137.202.10]:57166 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751048Ab3KMWuY (ORCPT ); Wed, 13 Nov 2013 17:50:24 -0500 Message-ID: <52840206.5020006@zytor.com> Date: Wed, 13 Nov 2013 14:49:42 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: jerry.hoemann@hp.com CC: rob@landley.net, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, matt.fleming@intel.com, yinghai@kernel.org, penberg@kernel.org, akpm@linux-foundation.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, vgoyal@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] Early use of boot service memory References: <1384222558-38527-1-git-send-email-jerry.hoemann@hp.com> <20131113224503.GB25344@anatevka.fc.hp.com> In-Reply-To: <20131113224503.GB25344@anatevka.fc.hp.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/13/2013 02:45 PM, jerry.hoemann@hp.com wrote: > > The changes in 3.9 to allow crash kernel to be allocated high helps. > But as you say, the default is still to allocate crash kernel low and > still susceptible to this problem. So, a kdump expert can work around it. > But, not everyone is a kdump expert. > > So, we can work to change the default, or encourage the distros > to always allocate high. Or, we change the call to efi_reserve_boot_services > not apply to all platforms. > > The problems for pre 3.9 based distros is worse as they don't have > ability to allocate crash kernel high. > But they won't have your new option, either, and that is still horribly manual and system-dependent. In other words, allocating the crashkernel high has ALL the advantages, plus a few more, and NONE of the disadvantages. -hpa