From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755963AbbAWRCv (ORCPT ); Fri, 23 Jan 2015 12:02:51 -0500 Received: from mail.skyhub.de ([78.46.96.112]:39466 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754267AbbAWRCt (ORCPT ); Fri, 23 Jan 2015 12:02:49 -0500 Date: Fri, 23 Jan 2015 18:02:43 +0100 From: Borislav Petkov To: Joerg Roedel Cc: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Konrad Rzeszutek Wilk , x86@kernel.org, linux-kernel@vger.kernel.org, Joerg Roedel Subject: Re: [PATCH 3/3] x86, crash: Allocate enough low-mem when crashkernel=high Message-ID: <20150123170243.GG22635@pd.tnic> References: <1420555874-11506-1-git-send-email-joro@8bytes.org> <1420555874-11506-4-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1420555874-11506-4-git-send-email-joro@8bytes.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 06, 2015 at 03:51:14PM +0100, Joerg Roedel wrote: > From: Joerg Roedel > > When the crashkernel is loaded above 4GiB in memory the > first kernel only allocates 72MiB of low-memory for the DMA > requirements of the second kernel. On systems with many > devices this is not enough and causes device driver > initialization errors and failed crash dumps. Set this > default value to 256MiB to make sure there is enough memory This upper limit of 256 looks arbitrary. Are we going to raise it a couple of years from now if it becomes insufficient then? It probably won't be easy but is there some more reliable way to allocate enough memory for DMA on a say per-system basis or whatever...? Probably not but let me ask it anyway. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --