Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932289AbaAWRw3 (ORCPT ); Thu, 23 Jan 2014 12:52:29 -0500 Received: from mail-vb0-f49.google.com ([209.85.212.49]:52210 "EHLO mail-vb0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932264AbaAWRw0 (ORCPT ); Thu, 23 Jan 2014 12:52:26 -0500 MIME-Version: 1.0 In-Reply-To: <52E155A8.7000206@hp.com> References: <1390426438-31252-1-git-send-email-Waiman.Long@hp.com> <1390426438-31252-2-git-send-email-Waiman.Long@hp.com> <20140123100751.GS30183@twins.programming.kicks-ass.net> <52E14D67.4000202@hp.com> <52E155A8.7000206@hp.com> Date: Thu, 23 Jan 2014 09:52:25 -0800 X-Google-Sender-Auth: rLh8L1xG5xeS3fjwnPq_3wltyNQ Message-ID: Subject: Re: [PATCH v10 1/4] qrwlock: A queue read/write lock implementation From: Linus Torvalds To: Waiman Long Cc: Peter Zijlstra , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Arnd Bergmann , "linux-arch@vger.kernel.org" , "the arch/x86 maintainers" , Linux Kernel Mailing List , Steven Rostedt , Andrew Morton , Michel Lespinasse , Andi Kleen , Rik van Riel , "Paul E. McKenney" , Raghavendra K T , George Spelvin , Tim Chen , "Chandramouleeswaran, Aswin" , Scott J Norton Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 23, 2014 at 9:47 AM, Waiman Long wrote: > > Thank for the info. I am less familiar with that kind of issues on other > architecture. I will add a smp_mb__after_atomic_dec() & send out a new > patch. SInce it's the unlock path,. you need to use the "mb__*before*" versions, since presumably you want to protect what is inside the lock from leaking out, not some random thing after the lock from leaking in.. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/