Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933854AbbGUTWz (ORCPT ); Tue, 21 Jul 2015 15:22:55 -0400 Received: from mail-ig0-f177.google.com ([209.85.213.177]:37080 "EHLO mail-ig0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933377AbbGUTWy (ORCPT ); Tue, 21 Jul 2015 15:22:54 -0400 MIME-Version: 1.0 In-Reply-To: <20150721085846.GA23020@dhcp-128-28.nay.redhat.com> References: <1437304064-9916-1-git-send-email-bhe@redhat.com> <20150719145320.GB9968@dhcp-17-102.nay.redhat.com> <20150721073123.GA30649@dhcp-129-220.nay.redhat.com> <20150721075011.GC16747@dhcp-128-28.nay.redhat.com> <20150721082343.GC30649@dhcp-129-220.nay.redhat.com> <20150721085846.GA23020@dhcp-128-28.nay.redhat.com> Date: Tue, 21 Jul 2015 12:22:53 -0700 X-Google-Sender-Auth: -ya0VGy1eHvuz8o_MNt7T5G9WVM Message-ID: Subject: Re: [PATCH v2] Do not reserve crashkernel high memory if crashkernel low memory reserving failed From: Yinghai Lu To: Baoquan He Cc: Dave Young , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Andrew Morton , Jiri Kosina , Vivek Goyal , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 887 Lines: 27 On Tue, Jul 21, 2015 at 1:58 AM, Baoquan He wrote: > Maybe system which don't need low memory is rare, only for testing? No, it is not rare. All recent intel based systems with iommu support does not need low. And those systems get punished by following patch: | commit 94fb9334182284e8e7e4bcb9125c25dc33af19d4 | Author: Joerg Roedel | Date: Wed Jun 10 17:49:42 2015 +0200 | | x86/crash: Allocate enough low memory when crashkernel=high that reserve 256M low always. and those 256M get wasted. That commit should only be used to workaround some systems that have partial iommu support. Yinghai -- 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/