From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753385Ab3GHBPN (ORCPT ); Sun, 7 Jul 2013 21:15:13 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:19546 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753321Ab3GHBPL (ORCPT ); Sun, 7 Jul 2013 21:15:11 -0400 Message-ID: <51DA127E.3040706@oracle.com> Date: Sun, 07 Jul 2013 21:14:38 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Ingo Molnar CC: Peter Zijlstra , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [Patch v5 0/9] liblockdep: userspace lockdep References: <1371163284-6346-1-git-send-email-sasha.levin@oracle.com> <20130626122408.GJ28407@twins.programming.kicks-ass.net> <20130626155325.GB7399@gmail.com> <51CB4328.7010006@oracle.com> <20130627090722.GC4398@gmail.com> <51CC4461.50207@oracle.com> In-Reply-To: <51CC4461.50207@oracle.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/27/2013 09:55 AM, Sasha Levin wrote: > On 06/27/2013 05:07 AM, Ingo Molnar wrote: >> >> * Sasha Levin wrote: >> >>> On 06/26/2013 11:53 AM, Ingo Molnar wrote: >>>>> Ingo, I don't think I see anything holding this back; however I remember >>>>>> reading some email about people not liking stuff like this living in the >>>>>> tools/ directory or such. >>>>>> >>>>>> Will you pick this up? >>>> So I'd really be interested in how interesting/useful this is to userspace >>>> developers? Does it work for something complex as Firefox, or Apache, to >>>> the extent they make use of these locking APIs? >>> >>> So far I've tested it on Firefox, Apache, QEMU, LKVM, GCC and random >>> smallish programs. I haven't really done full testing for each of those, >>> but just made sure that liblockdep behaves as it supposed to. I'm >>> guessing that with further work it will dig up actual issues. >> >> The other issue is that with lock classes disabled you have to hit an >> actual deadlock to trigger any output. >> >> I.e. much of the power of lockdep is diminished :-/ When actual deadlocks >> are triggered then it's not particularly complex to debug user-space apps: >> gdb the hung task(s) and look at the backtraces. > > Lock classes are disabled only if you're using the LD_PRELOAD method of > testing. If you actually re-compile your code with the library (by just > including the header and setting a #define to enable it) you will have > lock classes. Hi Ingo, Just wondering if you're planning on pushing it over to Linus from your tree, or should I go ahead and do it on my own? Thanks, Sasha