From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265054AbUETOB7 (ORCPT ); Thu, 20 May 2004 10:01:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265108AbUETOB7 (ORCPT ); Thu, 20 May 2004 10:01:59 -0400 Received: from mx2.elte.hu ([157.181.151.9]:64213 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S265054AbUETOB6 (ORCPT ); Thu, 20 May 2004 10:01:58 -0400 Date: Thu, 20 May 2004 16:03:30 +0200 From: Ingo Molnar To: Ricky Beam Cc: Linux Kernel Mail List Subject: Re: overlaping printk Message-ID: <20040520140330.GA1499@elte.hu> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.26.8-itk2 (ELTE 1.1) SpamAssassin 2.63 ClamAV 0.65 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Ricky Beam wrote: > It looks like somewhere in the path of release_console_sem() more than > one CPU is running the log. [...] the problem is this code in printk: if (oops_in_progress) { /* If a crash is occurring, make sure we can't deadlock */ spin_lock_init(&logbuf_lock); /* And make sure that we print immediately */ init_MUTEX(&console_sem); } so two crashes on two separate CPUs can go on in parallel. The problem is not constrained to the serial line - i've seen it on VGA too (albeit there it's much more rare). Ingo