From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756684Ab3AaThr (ORCPT ); Thu, 31 Jan 2013 14:37:47 -0500 Received: from terminus.zytor.com ([198.137.202.10]:42664 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751690Ab3AaTho (ORCPT ); Thu, 31 Jan 2013 14:37:44 -0500 Message-ID: <510AC79F.4030300@zytor.com> Date: Thu, 31 Jan 2013 11:35:59 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Shuah Khan CC: Yinghai Lu , Konrad Rzeszutek Wilk , Konrad Rzeszutek Wilk , "Eric W. Biederman" , Thomas Gleixner , Ingo Molnar , Andrew Morton , Borislav Petkov , Jan Kiszka , Jason Wessel , linux-kernel@vger.kernel.org, Joerg Roedel Subject: Re: [PATCH v7u1 26/31] x86: Don't enable swiotlb if there is not enough ram for it References: <20130109132409.GB18395@phenom.dumpdata.com> <87d2xeul5v.fsf@xmission.com> <20130111163548.GB25620@phenom.dumpdata.com> <20130118155535.GJ9973@phenom.dumpdata.com> <20130124153924.GA5943@konrad-lan.dumpdata.com> In-Reply-To: X-Enigmail-Version: 1.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/31/2013 11:28 AM, Shuah Khan wrote: > On Mon, Jan 28, 2013 at 8:44 PM, Yinghai Lu wrote: >> On Mon, Jan 28, 2013 at 6:27 PM, Shuah Khan wrote: >>> On Thu, Jan 24, 2013 at 2:50 PM, Yinghai Lu wrote: >>> >>> Your for-x86-boot git boots on AMD system I have. However, with >>> memmap=4095$1M option, it panics very early in boot. I don't have >>> physical access to the console and I will try to get you the panic >>> information tomorrow. >> >> panic is good, but it is supposed some kind of late.. >> > > It is a very early panic, however it is not specific to your git. It > happens on 3.4, 3.8-rc4. You can disregard the early panic for your > git. > Knocking out 4095 bytes is kind of an unusual action, however, assuming the kernel is running at 16 MiB as normal then it should just work... memmap=4095M$1M as was shown later is another matter... there the kernel will be living inside the reserved region, and yes, at that point it is panic time since there is nothing the kernel can do about it. -hpa