From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964868AbXBOChB (ORCPT ); Wed, 14 Feb 2007 21:37:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964869AbXBOChA (ORCPT ); Wed, 14 Feb 2007 21:37:00 -0500 Received: from fencepost.gnu.org ([199.232.76.164]:40902 "EHLO fencepost.gnu.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964868AbXBOChA (ORCPT ); Wed, 14 Feb 2007 21:37:00 -0500 Subject: Two unclear places in lockdep-design.txt From: Pavel Roskin To: linux-kernel@vger.kernel.org, Ingo Molnar Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Wed, 14 Feb 2007 21:36:58 -0500 Message-Id: <1171507018.3215.5.camel@dv> Mime-Version: 1.0 X-Mailer: Evolution 2.9.91 (2.9.91-2.fc7) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, Ingo! Many thanks for the lockdep validator! It has helped me immensely. However, lockdep-design.txt has been pretty hard to read for me. It would be great if you find an opportunity to clarify two things in the documentation. 1) What is a lock dependency? What does "L1 -> L2" mean? Does it mean that L1 should be first or second to be acquired? 2) What is "ever held with hardirqs enabled"? Does it mean that the lock was used in the code where hardirqs were enabled, or that it _also_ didn't disable hardirqs by itself (e.g. by spin_lock_irq)? I suspect the later is the case. I wish I could submit a patch for the documentation, but I still don't understand much of the theory. Still, I was able to interpret the error messages in a way that allows me to fix the locking issues in some drivers. -- Regards, Pavel Roskin