From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933480AbcBQAR1 (ORCPT ); Tue, 16 Feb 2016 19:17:27 -0500 Received: from e37.co.us.ibm.com ([32.97.110.158]:41860 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933384AbcBQAR0 (ORCPT ); Tue, 16 Feb 2016 19:17:26 -0500 X-IBM-Helo: d03dlp03.boulder.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org Date: Tue, 16 Feb 2016 16:17:28 -0800 From: "Paul E. McKenney" To: Boqun Feng Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , sasha.levin@oracle.com Subject: Re: [RFC v2 1/6] lockdep: Add helper functions of irq_context Message-ID: <20160217001728.GY6719@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1455602265-16490-1-git-send-email-boqun.feng@gmail.com> <1455602265-16490-2-git-send-email-boqun.feng@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1455602265-16490-2-git-send-email-boqun.feng@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16021700-0025-0000-0000-000021709525 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 16, 2016 at 01:57:40PM +0800, Boqun Feng wrote: > Add two helper functions of irq_context: > > task_irq_context(): return 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) > > is_same_irq_context(): compare whether two irq_context are the same. > Always return true if !(CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING) > > These two functions are added for the future use of irq_context by > LOCKED_ACCESS, because LOCKED_ACCESS needs to get the irq_context value > of a task when a data access happens rather than when a lock is > acquired, so it needs another way than getting the value from > held_lock::irq_context > > Signed-off-by: Boqun Feng Queued again for review and testing. ;-) Thanx, Paul > --- > kernel/locking/lockdep.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index 60ace56..f36df37 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -2839,6 +2839,16 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) > return 1; > } > > +static unsigned int task_irq_context(struct task_struct *task) > +{ > + return 2 * (task->hardirq_context ? 1 : 0) + task->softirq_context; > +} > + > +static bool is_same_irq_context(unsigned int ctx1, unsigned int ctx2) > +{ > + return ctx1 == ctx2; > +} > + > static int separate_irq_context(struct task_struct *curr, > struct held_lock *hlock) > { > @@ -2847,8 +2857,7 @@ static int separate_irq_context(struct task_struct *curr, > /* > * Keep track of points where we cross into an interrupt context: > */ > - hlock->irq_context = 2*(curr->hardirq_context ? 1 : 0) + > - curr->softirq_context; > + hlock->irq_context = task_irq_context(curr); > if (depth) { > struct held_lock *prev_hlock; > > @@ -2880,6 +2889,9 @@ static inline int mark_irqflags(struct task_struct *curr, > return 1; > } > > +#define task_irq_context(task) 0 > +#define is_same_irq_context(ctx1, ctx2) true > + > static inline int separate_irq_context(struct task_struct *curr, > struct held_lock *hlock) > { > -- > 2.7.1 >