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 S1752225AbcC3LHk (ORCPT <rfc822;w@1wt.eu>);
	Wed, 30 Mar 2016 07:07:40 -0400
Received: from mail-vk0-f52.google.com ([209.85.213.52]:35711 "EHLO
	mail-vk0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1750749AbcC3LHi (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 30 Mar 2016 07:07:38 -0400
MIME-Version: 1.0
Reply-To: sedat.dilek@gmail.com
In-Reply-To: <20160330103601.GT3408@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>
	<20160330095954.GB14352@fixme-laptop.cn.ibm.com>
	<20160330103601.GT3408@twins.programming.kicks-ass.net>
Date: Wed, 30 Mar 2016 13:07:37 +0200
Message-ID: <CA+icZUXAUV215UZ9MpirpyQFHM4W7W73Fz4SyoodLXsPzzp32g@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: Boqun Feng <boqun.feng@gmail.com>, 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 12:36 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, Mar 30, 2016 at 05:59:54PM +0800, Boqun Feng wrote:
>> > @@ -3164,6 +3181,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
>> >     hlock->acquire_ip = ip;
>> >     hlock->instance = lock;
>> >     hlock->nest_lock = nest_lock;
>> > +   hlock->irq_context = 2*(!!curr->hardirq_context) + !!curr->softirq_context;
>> >     hlock->trylock = trylock;
>> >     hlock->read = read;
>> >     hlock->check = check;
>>
>> This is just for cleaning up, right? However ->hardirq_context and
>> ->softirq_context only defined when CONFIG_TRACE_IRQFLAGS=y.
>
> Ah, that is the reason it was in a 'funny' place.
>
> The other reason is that we're careful to reduce hardirq_context to 0,1
> but don't do so for softirq_context.
>
>> So we should use macro like current_hardirq_context() here? Or
>> considering the two helpers introduced in my RFC:
>>
>> http://lkml.kernel.org/g/1455602265-16490-2-git-send-email-boqun.feng@gmail.com
>>
>> if you don't think that overkills ;-)
>
> Yeah, that might work, although I would like to keep the !! on both,
> makes me worry less.

Can you CC me on any new patches in this area?

Thanks.

- Sedat -