From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from storix.com (unknown [206.71.178.18]) by ozlabs.org (Postfix) with ESMTP id E0885DDEE2 for ; Sat, 21 Apr 2007 07:05:15 +1000 (EST) Message-ID: <46292B07.3030907@storix.com> Date: Fri, 20 Apr 2007 14:05:11 -0700 From: David Huffman MIME-Version: 1.0 To: Nathan Lynch , linuxppc-dev@ozlabs.org Subject: Re: Kernel Panic booting cdrom References: <46202254.1090606@storix.com> <20070414044529.GE6062@localdomain> <4623F574.1030804@storix.com> <20070417054537.GF6062@localdomain> In-Reply-To: <20070417054537.GF6062@localdomain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Nathan, I think I determined why I received a kernel panic and the numa=off argument fixed the problem. When we boot from cdrom we specify maxcpus=1 as a kernel argument. A system with numa enabled fails. I plan on adding numa=off whenever I use maxcpus=1, but I wonder if you could answer a question for me. I originally was told that in the case where I am booting a basic system into an initrd instead of in normal mode, I should use maxcpus=1 because there may be power and cooling daemons that are not running and try to limit the system resources by limiting the number of cpus. Does this sound right? I can successfully boot a cdrom without the maxcpus flag on an SMP system but maybe it is typically not a good idea? I can prevent the kernel panics by removing maxcpus=1 and not adding numa=off. I am a little more informed about numa (now), but I am fuzzy as to all the implications with allowing more cpus for cdrom install media. The maxcpus=1 argument was something we added to our install boot media years ago and few here remember why it was such a great idea. The power/resource management was the only thing we could come up with. David Huffman Storix, Inc Nathan Lynch wrote: > David Huffman wrote: > >> Nathan, >> >> Thank you very much for the info. This worked to get the system booted >> from cdrom. However, in normal mode, the numa=off argument is not in the >> yaboo.conf file. Any idea why it works without it in normal mode, but >> requires numa=off when using the same kernel and booting from cdrom? >> > > No, that doesn't make sense to me. If you'd like to dig deeper into > it, diff -u the output of dmesg from both boots. (and please copy the > list next time, thanks :) >