From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751250AbaALUBJ (ORCPT ); Sun, 12 Jan 2014 15:01:09 -0500 Received: from merlin.infradead.org ([205.233.59.134]:38284 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751028AbaALUBH (ORCPT ); Sun, 12 Jan 2014 15:01:07 -0500 Date: Sun, 12 Jan 2014 21:00:49 +0100 From: Peter Zijlstra To: Oleg Nesterov Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Thomas Gleixner , Steven Rostedt , Paul McKenney , Linus Torvalds Subject: Re: [PATCH 0/1] lockdep: Kill held_lock->check and "int check" arg of __lock_acquire() Message-ID: <20140112200049.GO7572@laptop.programming.kicks-ass.net> References: <20140109111516.GE7572@laptop.programming.kicks-ass.net> <20140109163120.GA8038@redhat.com> <20140109170823.GF7572@laptop.programming.kicks-ass.net> <20140112094041.GB31809@gmail.com> <20140112174532.GA12147@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140112174532.GA12147@redhat.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 12, 2014 at 06:45:32PM +0100, Oleg Nesterov wrote: > But could someone please explain me what should lockdep_no_validate > actually do? 1704f47b5 "lockdep: Add novalidate class for dev->mutex > conversion" doesn't tell which kind of warnings it tries to avoid, > and it looks buggy (see another email from me). It should disable lock-order checks for the locks that set that as class. So we can still do the simple checks like detect if we free memory with a held lock in and make sure we do not return to userspace with a held lock; but the class should not participate in the lock graph. I'll have a look at your earlier email again; I did note the question but it slipped my mind :/