Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752849Ab3CROqN (ORCPT ); Mon, 18 Mar 2013 10:46:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40621 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751671Ab3CROqL (ORCPT ); Mon, 18 Mar 2013 10:46:11 -0400 Date: Mon, 18 Mar 2013 10:46:04 -0400 From: Vivek Goyal To: Yinghai Lu Cc: "Eric W. Biederman" , "H. Peter Anvin" , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , WANG Chao , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86, kdump: Set crashkernel_low automatically Message-ID: <20130318144603.GA20743@redhat.com> References: <20130311182655.GB12107@redhat.com> <513E2695.3080707@zytor.com> <513E28B8.3000502@zytor.com> <20130311191031.GD12107@redhat.com> <20130311193824.GA14738@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1490 Lines: 35 On Mon, Mar 11, 2013 at 12:44:15PM -0700, Yinghai Lu wrote: > On Mon, Mar 11, 2013 at 12:39 PM, Yinghai Lu wrote: > > On Mon, Mar 11, 2013 at 12:38 PM, Vivek Goyal wrote: > >>> No need to use crashkernel_high, we can just cashkernel=X@Y instead. > >> > >> crashkernel=X@Y is little different. It assumes user knows the memory > >> map and location "Y" is fixed. There might not be any memory at "Y". > > > > then use crashkernel=4G? > > I re attached -v2 and -v3. > > I'm ok that any one is applied or two get applied all together. > > only affect 64bit > -v2: try under under 896M, then 4G, then MAXMEM > -v3: auto set crashkernel_low with swiotlb size. So, what's the resolution on this issue. Is the verdict that we always reserve high. Update your kexec-tools to cope with that. For swiotlb issue, modify kexec-tools to copy low memory in backup region and give low memory to second kernel for software iotlb? I am assuming that updating tools will not help with loading and using of 32bit bzImage. So user needs to use crashkernel=X@Y syntax to cope with that? (Given the fact that copying code around after crash carries the greater risk of ongoing DMA on destination location). Thanks Vivek -- 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/