Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756164Ab3JXTS6 (ORCPT ); Thu, 24 Oct 2013 15:18:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17929 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755884Ab3JXTS5 (ORCPT ); Thu, 24 Oct 2013 15:18:57 -0400 Date: Thu, 24 Oct 2013 15:18:21 -0400 From: Vivek Goyal To: Yinghai Lu Cc: WANG Chao , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Pekka Enberg , Jacob Shin , Andrew Morton , "Eric W. Biederman" , "kexec@lists.infradead.org" , Linux Kernel Mailing List Subject: Re: [PATCH] x86, kdump: crashkernel=X try to reserve below 896M first, then try below 4G, then MAXMEM Message-ID: <20131024191821.GE2322@redhat.com> References: <1381751200-27376-1-git-send-email-chaowang@redhat.com> <20131015144810.GI31215@redhat.com> <20131018123837.GB2277@redhat.com> <20131021151643.GA20669@redhat.com> <20131024140241.GA2322@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: 1560 Lines: 34 On Thu, Oct 24, 2013 at 12:15:25PM -0700, Yinghai Lu wrote: > On Thu, Oct 24, 2013 at 7:02 AM, Vivek Goyal wrote: > > On Wed, Oct 23, 2013 at 11:11:51PM -0700, Yinghai Lu wrote: > > > > Hence both crashkernel=xM and crashkernel=XM,high have their own usage. > > We have been using crashkernel=xM and we know it works. So extending it > > to be able to allocate memory from higher regions, if sufficient memory > > is not available in lower regions makes sense. Memory reservation below > > 4G is more efficient due to not requiring swiotlb. And crashkernel=xM > > has been working for us and users are familiar with it. > > > > So I don't see a point that why would you try to block any move to > > extend crashkernel=xM semantics. > > Make the thing simple. > Keep them separately, leave crashkernel=xM to old kexec-tools mostly > and keep crashkernel=xM,high to newer kexec-tools as needed. I am keeping things simple by making sure that both old kexec-tools and new kexec-tools can use crashkernel=xM and one does not have to choose between two based on what kexec-tools version you are using. Also keeping things simple by not trying to *impose* a new crashkernel= syntax on existing crashkernel=xM users. Hence extending the semantics of crashkernel=xM makes sense to me. 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/