Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756104Ab3CRX07 (ORCPT ); Mon, 18 Mar 2013 19:26:59 -0400 Received: from mail-ob0-f177.google.com ([209.85.214.177]:61430 "EHLO mail-ob0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752717Ab3CRX05 (ORCPT ); Mon, 18 Mar 2013 19:26:57 -0400 MIME-Version: 1.0 In-Reply-To: <51479AAD.7040209@zytor.com> References: <514783B4.2030401@zytor.com> <1363641957-5247-1-git-send-email-yinghai@kernel.org> <51479AAD.7040209@zytor.com> Date: Mon, 18 Mar 2013 16:26:57 -0700 X-Google-Sender-Auth: ZBmM9jWzVi-GWHEgNNFNPJ9JOQQ Message-ID: Subject: Re: [PATCH v3] x86, kdump: Set crashkernel_low automatically From: Yinghai Lu To: "H. Peter Anvin" Cc: Thomas Gleixner , Ingo Molnar , WANG Chao , Vivek Goyal , "Eric W. Biederman" , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 44 On Mon, Mar 18, 2013 at 3:52 PM, H. Peter Anvin wrote: > On 03/18/2013 02:25 PM, Yinghai Lu wrote: >> Current code does not set low range for crashkernel if the user >> does not specify that. >> >> That cause regressions on system that does not support intel_iommu >> properly. >> >> Chao said that his system does work well on 3.8 without extra parameter. >> even iommu does not work with kdump. >> >> Set crashkernel_low automatically if the user does not specify that. >> >> For system that does support IOMMU with kdump properly, user could >> specify crashkernel_low=0 to save that 72M low ram. >> >> -v3: add swiotlb_size() according to Konrad. >> >> Reported-by: WANG Chao >> Tested-by: WANG Chao >> Signed-off-by: Yinghai Lu > > Can we get a bit more of an explanation instead of "and etc 8M"? At > least a hint of what kind of objects would go in there... now only have: swiotlb overflow buffer v_overflow_buffer = alloc_bootmem_low_pages_nopanic( PAGE_ALIGN(io_tlb_overflow)); and /* * When the IOMMU overflows we return a fallback buffer. This sets the size. */ static unsigned long io_tlb_overflow = 32*1024; so it is 32K, and I round it to 8M. -- 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/