From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752581Ab1LULSY (ORCPT ); Wed, 21 Dec 2011 06:18:24 -0500 Received: from casper.infradead.org ([85.118.1.10]:43583 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752423Ab1LULSW (ORCPT ); Wed, 21 Dec 2011 06:18:22 -0500 Message-Id: <20111221105739.798864333@chello.nl> User-Agent: quilt/0.48-1 Date: Wed, 21 Dec 2011 11:57:39 +0100 From: Peter Zijlstra To: Linus Torvalds , "Ted Ts'o" , Greg KH , Ingo Molnar , Thomas Gleixner , akpm@linux-foundation.org Cc: linux-kernel Subject: [RFC][PATCH 0/7] improve printk reliability Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, So these are my current efforts to make my own console output more reliable. I've hit every deadlock described in this series and a few more. With these patches applied I can printk() and WARN() from inside scheduler context and not have my machine deadlock, even without the aid of early_printk(). While I'll go an remove the sole printk() I found in the scheduler so that we don't have to rely on the console doing this, it is good to have a reliable console that can do this. As it stands some of the patches, the semaphore one in particular, are really too ugly to live so I won't push those but wanted to share anyway. Debugging this was 'fun', and I really hope to not have to do it again :-)