From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758201AbYDRHcz (ORCPT ); Fri, 18 Apr 2008 03:32:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750773AbYDRHcr (ORCPT ); Fri, 18 Apr 2008 03:32:47 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:46147 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750722AbYDRHcr (ORCPT ); Fri, 18 Apr 2008 03:32:47 -0400 Date: Fri, 18 Apr 2008 00:32:17 -0700 From: Andrew Morton To: Ben Hutchings , linux-kernel@vger.kernel.org, Ingo Molnar , Arjan van de Ven Subject: Re: [PATCH][RFC] Add default CPU topology information Message-Id: <20080418003217.94e25f2f.akpm@linux-foundation.org> In-Reply-To: <20080418001024.7377c52d.akpm@linux-foundation.org> References: <20080331114412.GH21637@solarflare.com> <20080418001024.7377c52d.akpm@linux-foundation.org> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 18 Apr 2008 00:10:24 -0700 Andrew Morton wrote: > On Mon, 31 Mar 2008 12:44:13 +0100 Ben Hutchings wrote: > > > Not all architectures and configurations define CPU topology information. > > This can result in an empty topology directory in sysfs, and requires > > in-kernel users to protect all uses with #ifdef - see > > . > > > > The documentation of CPU topology specifies what the defaults should be > > if only partial information is available from the hardware. So we can > > provide these defaults as a fallback. > > > > This patch: > > > > - Adds default definitions of the 4 topology macros to > > include/asm-generic/topology.h. > > - Changes include/asm-*/topology.h to include > > unconditionally. > > - Changes drivers/base/topology.c to use the topology macros unconditionally > > and to cope with definitions that aren't lvalues. > > - Updates documentation accordingly. > > I get a huuuuuuuge crash early in boot on the t61p dual x86_64 laptop. > Before netconsole has started and it has no serial port, so all I have is a > partially-scrolled-off jpg, sorry. > > I'll drop the patch. > > http://userweb.kernel.org/~akpm/p4175278.jpg > http://userweb.kernel.org/~akpm/config-t61p.txt > http://userweb.kernel.org/~akpm/dmesg-t61p.txt > > > If I didn't have all that wrong crap on the stack we'd have a full > trace here. I have CONFIG_FRAME_POINTER=y, but that doesn't seem to > have helped. > ooh, I just discovered kstack=. That should be hoisted up to core kernel then pushed out to other architectures, not hidden in x86_64 code. But first I guess it should be make to work - it fails miserably, because only one of our seventy fix stack-dumping functions actually looks at it. This: --- a/arch/x86/kernel/traps_64.c~a +++ a/arch/x86/kernel/traps_64.c @@ -426,7 +426,7 @@ _show_stack(struct task_struct *tsk, str printk(" %016lx", *stack++); touch_nmi_watchdog(); } - show_trace(tsk, regs, sp, bp); +// show_trace(tsk, regs, sp, bp); } void show_stack(struct task_struct *tsk, unsigned long * sp) works heaps better. Here's the rest of your oops: http://userweb.kernel.org/~akpm/p4175279.jpg I'd be suspecting startup ordering problems - maybe the page allocator isn't ready yet. otoh, it _should_ be ready by the time we run init_sched_domains().