From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757096AbcCaPml (ORCPT ); Thu, 31 Mar 2016 11:42:41 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:36870 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756721AbcCaPmk (ORCPT ); Thu, 31 Mar 2016 11:42:40 -0400 Date: Thu, 31 Mar 2016 17:42:34 +0200 From: Peter Zijlstra To: Boqun Feng Cc: Ingo Molnar , Alfredo Alvarez Fernandez , Linus Torvalds , Sedat Dilek , "Theodore Ts'o" , linux-fsdevel , LKML Subject: Re: [Linux-v4.6-rc1] ext4: WARNING: CPU: 2 PID: 2692 at kernel/locking/lockdep.c:2017 __lock_acquire+0x180e/0x2260 Message-ID: <20160331154234.GA3448@twins.programming.kicks-ass.net> References: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160330095954.GB14352@fixme-laptop.cn.ibm.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 Wed, Mar 30, 2016 at 05:59:54PM +0800, Boqun Feng wrote: > 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 ;-) I changed it into the below; since I did significant edits, let me know if you disagree and / or want your name taken off. --- Subject: lockdep: Add task_irq_context() From: Boqun Feng Date: Tue, 16 Feb 2016 13:57:40 +0800 task_irq_context(): returns the encoded irq_context of the task, the return value is encoded in the same as ->irq_context of held_lock. Always return 0 if !(CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING) Cc: Lai Jiangshan Cc: Mathieu Desnoyers Cc: Steven Rostedt Cc: Ingo Molnar Cc: Josh Triplett Cc: sasha.levin@oracle.com Cc: "Paul E. McKenney" Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Link: http://lkml.kernel.org/r/1455602265-16490-2-git-send-email-boqun.feng@gmail.com --- kernel/locking/lockdep.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2932,6 +2932,11 @@ static int mark_irqflags(struct task_str return 1; } +static inline unsigned int task_irq_context(struct task_struct *task) +{ + return 2 * !!task->hardirq_context + !!task->softirq_context; +} + static int separate_irq_context(struct task_struct *curr, struct held_lock *hlock) { @@ -2940,8 +2945,6 @@ static int separate_irq_context(struct t /* * Keep track of points where we cross into an interrupt context: */ - hlock->irq_context = 2*(curr->hardirq_context ? 1 : 0) + - curr->softirq_context; if (depth) { struct held_lock *prev_hlock; @@ -2973,6 +2976,11 @@ static inline int mark_irqflags(struct t return 1; } +static inline unsigned int task_irq_context(struct task_struct *task) +{ + return 0; +} + static inline int separate_irq_context(struct task_struct *curr, struct held_lock *hlock) { @@ -3241,6 +3249,7 @@ static int __lock_acquire(struct lockdep hlock->acquire_ip = ip; hlock->instance = lock; hlock->nest_lock = nest_lock; + hlock->irq_context = task_irq_context(curr); hlock->trylock = trylock; hlock->read = read; hlock->check = check;