Received: by 10.223.185.116 with SMTP id b49csp6038821wrg; Wed, 28 Feb 2018 02:59:42 -0800 (PST) X-Google-Smtp-Source: AH8x225kBNmNphtS0X6K7njHRFuZ6SaAjg+2bCak5C7ebEtwyki0CLNkxt8D2pBjGgHDO6hI8sq9 X-Received: by 2002:a17:902:70c9:: with SMTP id l9-v6mr17267678plt.67.1519815582326; Wed, 28 Feb 2018 02:59:42 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1519815582; cv=none; d=google.com; s=arc-20160816; b=OErwwsbO8moQ2Z5BWDOX5+2e+nEkzpmfceWtCV1jWe0oBXznZ0nzU0kMak5jWS7Q6J EGAYphjJY7NDmiK80Y8YoflNFVVnZwZ6mZGT1elSOV+mGm8tLKRI8Rc1+Fg3bGXleSmR xKoRP+GhS5jOj889euQpbraiw2zbMZ12gJjUzz+4dMJKDhEXIMtwOZ2Lz1qzR+TFKBv7 wr3UAAAVLJrRdLRxrJAI0yjW9WMZZQjya3hequiJZXYKScARw/VXt26An++8clOiHGud 5CS3wlLKGWz2ZI29cC2xvWH/BRrvBYHdxHPN2z3cTVQEUbaiwWCpYJ8/NnIjwZkXdydW vLnQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=VkgLQsdXZvkV2I0uOoMEO+u4NVnFrfIph9niIPOnatg=; b=eUAJWzdTijNpr6HznmigC7GPBe9+B4xune81IT+FPmw8RSUwX71tWshvtKnj0kq7hi HIcZ1vbNTjAzNZk0QkMg+W5eW1TIBFuqWUDGtzstLnEdxm2JV4vyajWiQyRUEE3SudEj m9f+aYEKrIjEDYtm+FgnxGFCjy1BqVAS+bjMFHo3680FgFGn+Vo+D0UwpNq3xFZartYw BFQ8q3q/cdXXzGhdCJf059uavYQiWRMmmGmBZ1B0xyhlMN/32TstoX/lBYSezagTtQPq nmwhSRtrGPmFVFCTmzCEYeNh4Yla3gTd6B/OwlGr53gJXu46KbjD21pdTguOIspRU886 LOng== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id k185si1053293pfc.277.2018.02.28.02.59.25; Wed, 28 Feb 2018 02:59:42 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752534AbeB1K6L (ORCPT + 99 others); Wed, 28 Feb 2018 05:58:11 -0500 Received: from foss.arm.com ([217.140.101.70]:47716 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752477AbeB1K6J (ORCPT ); Wed, 28 Feb 2018 05:58:09 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 485341435; Wed, 28 Feb 2018 02:58:09 -0800 (PST) Received: from edgewater-inn.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 19B1D3F318; Wed, 28 Feb 2018 02:58:09 -0800 (PST) Received: by edgewater-inn.cambridge.arm.com (Postfix, from userid 1000) id 4669A1AE53BC; Wed, 28 Feb 2018 10:58:11 +0000 (GMT) Date: Wed, 28 Feb 2018 10:58:11 +0000 From: Will Deacon To: Andrea Parri Cc: Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org, "Paul E . McKenney" , Alan Stern , Andrew Morton , Ivan Kokshaysky , Linus Torvalds , Matt Turner , Richard Henderson , Thomas Gleixner , linux-alpha@vger.kernel.org Subject: Re: [PATCH] locking/xchg/alpha: Remove memory barriers from the _local() variants Message-ID: <20180228105810.GB7681@arm.com> References: <1519704058-13430-1-git-send-email-parri.andrea@gmail.com> <20180227200830.GA3164@andrea> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180227200830.GA3164@andrea> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 27, 2018 at 09:08:31PM +0100, Andrea Parri wrote: > [+ Will] > > I'm not sure how this happened; Will, you at least figure as Reported-by: ;-) Thanks, this looks better to me. Have you build an Alpha kernel to check that the various cmpxchg variants are producing the expected asm? Will