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 S1760283AbcJRNDH (ORCPT <rfc822;w@1wt.eu>);
        Tue, 18 Oct 2016 09:03:07 -0400
Received: from bombadil.infradead.org ([198.137.202.9]:47949 "EHLO
        bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1754884AbcJRNDA (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 18 Oct 2016 09:03:00 -0400
Date: Tue, 18 Oct 2016 15:02:42 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <waiman.long@hpe.com>
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>,
        Tim Chen <tim.c.chen@linux.intel.com>, Terry Rudd <terry.rudd@hpe.com>,
        "Paul E. McKenney" <paulmck@us.ibm.com>, Jason Low <jason.low2@hp.com>,
        Chris Wilson <chris@chris-wilson.co.uk>,
        Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: Re: [PATCH -v4 5/8] locking/mutex: Add lock handoff to avoid
 starvation
Message-ID: <20161018130242.GX3117@twins.programming.kicks-ass.net>
References: <20161007145243.361481786@infradead.org>
 <20161007150211.196801561@infradead.org>
 <58051C5E.3030204@hpe.com>
 <5805218A.3050707@hpe.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <5805218A.3050707@hpe.com>
User-Agent: Mutt/1.5.23.1 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, Oct 17, 2016 at 03:07:54PM -0400, Waiman Long wrote:
> One more thing, I think it may be worthwhile to add another comment about
> what happens when the HANDOFF bit was set while we take the error path (goto
> err). As the actual handoff is serialized by the wait_lock, the code will
> still do the right thing. Either the next one in the queue will be handed
> off or it will be unlocked if the queue is empty.

Doesn't the next patch add just such a comment?