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 S1751914AbcBLWJO (ORCPT <rfc822;w@1wt.eu>);
	Fri, 12 Feb 2016 17:09:14 -0500
Received: from mx2.suse.de ([195.135.220.15]:33585 "EHLO mx2.suse.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751461AbcBLWJM (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Fri, 12 Feb 2016 17:09:12 -0500
Date: Fri, 12 Feb 2016 14:09:02 -0800
From: Davidlohr Bueso <dave@stgolabs.net>
To: Waiman Long <Waiman.Long@hpe.com>
Cc: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Ding Tianhong <dingtianhong@huawei.com>,
        Jason Low <jason.low2@hpe.com>,
        "Paul E. McKenney" <paulmck@us.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <Will.Deacon@arm.com>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Waiman Long <Waiman.Long@hp.com>
Subject: Re: [PATCH v2 1/4] locking/mutex: Add waiter parameter to
 mutex_optimistic_spin()
Message-ID: <20160212220902.GB16417@linux-uzut.site>
References: <1455298335-53229-1-git-send-email-Waiman.Long@hpe.com>
 <1455298335-53229-2-git-send-email-Waiman.Long@hpe.com>
 <20160212220249.GA16417@linux-uzut.site>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Disposition: inline
In-Reply-To: <20160212220249.GA16417@linux-uzut.site>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, 12 Feb 2016, Davidlohr Bueso wrote:

>This can be a really hot path, could we get rid of the waiter check and just
>introduce mutex_tro_to_acquire_waiter() or such and set the counter to -1 there?

Ah nm, I just realized why you do this :) For a second I thought that you called into
this directly from __mutex_lock_common.