From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753216AbcC3Mqj (ORCPT <rfc822;w@1wt.eu>);
	Wed, 30 Mar 2016 08:46:39 -0400
Received: from mail-vk0-f65.google.com ([209.85.213.65]:33535 "EHLO
	mail-vk0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752985AbcC3Mqh (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 30 Mar 2016 08:46:37 -0400
MIME-Version: 1.0
Reply-To: sedat.dilek@gmail.com
In-Reply-To: <20160330124356.GD3430@twins.programming.kicks-ass.net>
References: <CA+icZUVLbBD4xc7OjV112KHhxAnW_t3Fcpjht2SjVAo3Ds-Hrg@mail.gmail.com>
	<CA+icZUXgSK5VY7zJQ0bZZwKZmeYS+A7BRQD2fBBSzK=sM2aMLw@mail.gmail.com>
	<CA+55aFw-YXACVasN4n0h03QWgWWwvBray2fcMScAnEn0Wy_Ohw@mail.gmail.com>
	<20160327204810.GW6356@twins.programming.kicks-ass.net>
	<20160329084701.GA9393@gmail.com>
	<20160330093659.GS3408@twins.programming.kicks-ass.net>
	<CA+icZUU-dFAzv-jKWt=D_wUN1NU6dGDcSTcB0AdisHkionFwMw@mail.gmail.com>
	<20160330124356.GD3430@twins.programming.kicks-ass.net>
Date: Wed, 30 Mar 2016 14:46:36 +0200
Message-ID: <CA+icZUV==b46jX-vUUQUVBweER2-3xxGGyC9QM5dK18Th5PdJw@mail.gmail.com>
Subject: Re: [Linux-v4.6-rc1] ext4: WARNING: CPU: 2 PID: 2692 at
 kernel/locking/lockdep.c:2017 __lock_acquire+0x180e/0x2260
From: Sedat Dilek <sedat.dilek@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
        Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "Theodore Ts'o" <tytso@mit.edu>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, Mar 30, 2016 at 2:43 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Mar 30, 2016 at 11:49:57AM +0200, Sedat Dilek wrote:
>> On Wed, Mar 30, 2016 at 11:36 AM, Peter Zijlstra <peterz@infradead.org> wrote:
>
>> > OK, so while the code in check_no_collision() seems sensible, it relies
>> > on borken bits.
>> >
>> > The whole chain_hlocks and /proc/lockdep_chains stuff appears to have
>> > been buggered from the start.
>> >
>> > The below patch should fix this.
>> >
>>
>> checkpatch.pl says...
>>
>> WARNING: Prefer seq_puts to seq_printf
>> #124: FILE: kernel/locking/lockdep_proc.c:145:
>> +                       seq_printf(m, "(buggered) ");
>
> Yeah, sod checkpatch ;-)
>
> What's in your /proc/lockdep_stats file?

Eat thiz!

$ sudo cat /proc/lockdep_stats
 lock-classes:                         2012 [max: 8191]
 direct dependencies:                  9638 [max: 32768]
 indirect dependencies:               39300
 all direct dependencies:            256286
 dependency chains:                   12869 [max: 65536]
 dependency chain hlocks:             49608 [max: 327680]
 in-hardirq chains:                     115
 in-softirq chains:                     458
 in-process chains:                   11504
 stack-trace entries:                154861 [max: 524288]
 combined max dependencies:       612572220
 hardirq-safe locks:                     61
 hardirq-unsafe locks:                 1032
 softirq-safe locks:                    169
 softirq-unsafe locks:                  949
 irq-safe locks:                        178
 irq-unsafe locks:                     1032
 hardirq-read-safe locks:                 4
 hardirq-read-unsafe locks:             226
 softirq-read-safe locks:                 8
 softirq-read-unsafe locks:             221
 irq-read-safe locks:                     9
 irq-read-unsafe locks:                 226
 uncategorized locks:                   216
 unused locks:                            0
 max locking depth:                      17
 max bfs queue depth:                   354
 chain lookup misses:                 12974
 chain lookup hits:                36326533
 cyclic checks:                       11430
 find-mask forwards checks:            3952
 find-mask backwards checks:          74700
 hardirq on events:                41715052
 hardirq off events:               41715056
 redundant hardirq ons:                 404
 redundant hardirq offs:           19500606
 softirq on events:                  220687
 softirq off events:                 220715
 redundant softirq ons:                   0
 redundant softirq offs:                  0
 debug_locks:                             1

- Sedat -