Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754965Ab1FFK1W (ORCPT ); Mon, 6 Jun 2011 06:27:22 -0400 Received: from merlin.infradead.org ([205.233.59.134]:45355 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753194Ab1FFK1U convert rfc822-to-8bit (ORCPT ); Mon, 6 Jun 2011 06:27:20 -0400 Subject: Re: [debug patch] printk: Add a printk killswitch to robustify NMI watchdog messages From: Peter Zijlstra To: Arne Jansen Cc: Ingo Molnar , Linus Torvalds , 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, linux-tip-commits@vger.kernel.org In-Reply-To: <4DECA525.7030503@die-jansens.de> References: <20110605151323.GA30590@elte.hu> <20110605152641.GA31124@elte.hu> <20110605153218.GA31471@elte.hu> <4DEBA9CC.4090503@die-jansens.de> <4DEBB05C.8090506@die-jansens.de> <4DEBB3DA.8060001@die-jansens.de> <20110605172052.GA1036@elte.hu> <4DEBBFF9.2030101@die-jansens.de> <20110605185957.GA3452@elte.hu> <4DEBD95B.6030901@die-jansens.de> <20110605194419.GA12965@elte.hu> <4DEBE3DF.70104@die-jansens.de> <1307350909.2353.7408.camel@twins> <4DECA525.7030503@die-jansens.de> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Mon, 06 Jun 2011 12:26:57 +0200 Message-ID: <1307356017.2353.7511.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 646 Lines: 14 On Mon, 2011-06-06 at 12:00 +0200, Arne Jansen wrote: > As expected this apparently fixes the problem. But are we confident > enough this is the true source? If it's really that simple, printk > calling into the scheduler, why am I the only one seeing this? Right, so apparently you have contention on console_sem and the up() actually does a wakeup. I'm still trying to figure out how to do that. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/