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 S1755322AbcHWUwt (ORCPT <rfc822;w@1wt.eu>);
        Tue, 23 Aug 2016 16:52:49 -0400
Received: from mga01.intel.com ([192.55.52.88]:39917 "EHLO mga01.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1752859AbcHWUws (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 23 Aug 2016 16:52:48 -0400
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.28,567,1464678000"; 
   d="scan'208";a="1040375045"
Message-ID: <1471985566.2916.18.camel@linux.intel.com>
Subject: Re: [RFC][PATCH 1/3] locking/mutex: Rework mutex::owner
From: Tim Chen <tim.c.chen@linux.intel.com>
To: Waiman Long <waiman.long@hpe.com>,
        Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Jason Low <jason.low2@hpe.com>,
        Ding Tianhong <dingtianhong@huawei.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <Will.Deacon@arm.com>, Ingo Molnar <mingo@redhat.com>,
        Imre Deak <imre.deak@intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Davidlohr Bueso <dave@stgolabs.net>, Terry Rudd <terry.rudd@hpe.com>,
        "Paul E. McKenney" <paulmck@us.ibm.com>, Jason Low <jason.low2@hp.com>
Date: Tue, 23 Aug 2016 13:52:46 -0700
In-Reply-To: <57BCAA48.6050202@hpe.com>
References: <20160823124617.015645861@infradead.org>
         <20160823124856.763266868@infradead.org> <57BCAA48.6050202@hpe.com>
Content-Type: text/plain; charset="UTF-8"
X-Mailer: Evolution 3.18.5.2 (3.18.5.2-1.fc23) 
Mime-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, 2016-08-23 at 15:55 -0400, Waiman Long wrote:
> On 08/23/2016 08:46 AM, Peter Zijlstra wrote:
> 
> I have 2 more comments about the code.
> 1) There are a couple of places where you only use 0x3 in mutex.c. They 
> should be replaced by the symbolic name instead.

May be easier to read if (owner & 0x3) and
(owner & ~0x3) are changed to something like 
_owner_flag(owner) and _owner_task(owner).

Tim

> 2) We should make __mutex_lock_slowpath() a noinline function just like 
> __mutex_lock_killable_slowpath() or __mutex_lock_interruptible_slowpath().
> 
> Cheers,
> Longman