From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761508AbYBTIOz (ORCPT ); Wed, 20 Feb 2008 03:14:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760167AbYBTIOa (ORCPT ); Wed, 20 Feb 2008 03:14:30 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:56495 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1760053AbYBTIO2 (ORCPT ); Wed, 20 Feb 2008 03:14:28 -0500 Date: Wed, 20 Feb 2008 00:15:05 -0800 (PST) Message-Id: <20080220.001505.196948168.davem@davemloft.net> To: mingo@elte.hu Cc: tony.luck@gmail.com, rdreier@cisco.com, linux-kernel@vger.kernel.org Subject: Re: Strange hang on ia64 with CONFIG_PRINTK_TIME=y From: David Miller In-Reply-To: <20080220081228.GA27036@elte.hu> References: <12c511ca0802141817i3295e83cxd7c05e07f2c54fea@mail.gmail.com> <12c511ca0802191440q6a2f5604xe6b563c32c3a90b2@mail.gmail.com> <20080220081228.GA27036@elte.hu> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) 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 From: Ingo Molnar Date: Wed, 20 Feb 2008 09:12:28 +0100 > > * Tony Luck wrote: > > > > Perhaps what is happening is that cpu0 comes online ... safely skips > > > over the early printk calls. Calls cpu_init() which sets up the > > > resources *it* needs (ar.k3 points to per-cpu space), and then > > > executes sched_init() which marks it safe for all printk's. Then > > > cpu1 comes up and does a printk before it gets to cpu_init(). > > > > I just tried Ingo's patch[1] on a 2.6.25-rc2 kernel with printk > > timestamps turned on ... and it booted just fine on my tiger4. The > > default path for non-boot cpus is from head.S to start_secondary(), > > and that calls cpu_init() pretty quickly. There shouldn't normally[2] > > be any printk() calls on the non-boot cpu before it is safe to do so. > > ok. I've queued up the patch again in sched.git, as a .25 fix. Can i add > your Tested-by and Acked-by tags? Acked-by: David S. Miller