From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754736Ab1FCMo0 (ORCPT ); Fri, 3 Jun 2011 08:44:26 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:53500 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751172Ab1FCMoZ (ORCPT ); Fri, 3 Jun 2011 08:44:25 -0400 MIME-Version: 1.0 In-Reply-To: <4DE8B13D.9020302@die-jansens.de> References: <20110405152729.232781355@chello.nl> <4DE64596.5010006@die-jansens.de> <1306946120.2497.606.camel@laptop> <4DE674EB.1000200@die-jansens.de> <1306951751.2497.626.camel@laptop> <1306953870.2497.627.camel@laptop> <4DE6936F.7090700@die-jansens.de> <1307092535.2353.2973.camel@twins> <4DE8B13D.9020302@die-jansens.de> From: Linus Torvalds Date: Fri, 3 Jun 2011 21:44:01 +0900 Message-ID: Subject: Re: [tip:sched/locking] sched: Add p->pi_lock to task_rq_lock() To: Arne Jansen Cc: Peter Zijlstra , mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, efault@gmx.de, npiggin@kernel.dk, akpm@linux-foundation.org, frank.rowand@am.sony.com, tglx@linutronix.de, mingo@elte.hu, linux-tip-commits@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 3, 2011 at 7:02 PM, Arne Jansen wrote: > > No, it doesn't trigger, but the hang is not as complete as I first > thought. A running iostat via ssh continues to give output for a while, > the serial console still reacts to return and prompts for login. But > after a while more and more locks up. The console locks as soon as I > sysrq-t. Is it the tty rescheduling bug? That would explain the printk's mattering. Remove the schedule_work() call from flush_to_ldisc() in drivers/tty/tty_buffer.c and see if the problem goes away. See the other discussion thread on lkml ("tty breakage in X (Was: tty vs workqueue oddities)") Hmm? Linus