From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84844C3279B for ; Fri, 6 Jul 2018 14:07:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 420C023EB6 for ; Fri, 6 Jul 2018 14:07:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 420C023EB6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-sky.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753993AbeGFOHj (ORCPT ); Fri, 6 Jul 2018 10:07:39 -0400 Received: from smtp2200-217.mail.aliyun.com ([121.197.200.217]:57816 "EHLO smtp2200-217.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753652AbeGFOHh (ORCPT ); Fri, 6 Jul 2018 10:07:37 -0400 X-Alimail-AntiSpam: AC=CONTINUE;BC=0.08794352|-1;CH=green;FP=0|0|0|0|0|-1|-1|-1;HT=e02c03312;MF=ren_guo@c-sky.com;NM=1;PH=DS;RN=12;RT=12;SR=0;TI=SMTPD_---.CN6tvVZ_1530886019; Received: from localhost(mailfrom:ren_guo@c-sky.com fp:SMTPD_---.CN6tvVZ_1530886019) by smtp.aliyun-inc.com(10.147.40.44); Fri, 06 Jul 2018 22:06:59 +0800 Date: Fri, 6 Jul 2018 22:06:59 +0800 From: Guo Ren To: Peter Zijlstra Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, daniel.lezcano@linaro.org, jason@lakedaemon.net, arnd@arndb.de, c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com, thomas.petazzoni@bootlin.com, wbx@uclibc-ng.org, green.hu@gmail.com Subject: Re: [PATCH V2 11/19] csky: Atomic operations Message-ID: <20180706140659.GB25190@guoren> References: <860b8db036b33d7b3648cb1f4ec827a53dc1a01b.1530465326.git.ren_guo@c-sky.com> <20180705175902.GF2530@hirez.programming.kicks-ass.net> <20180706114402.GB27148@guoren> <20180706120323.GW2476@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180706120323.GW2476@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 06, 2018 at 02:03:23PM +0200, Peter Zijlstra wrote: > > > Test-and-set with MB acting as ACQUIRE, ok. > > Em ... Ok, I'll try to use test-and-set function instead of it. > > "test-and-set" is just the name of this type of spinlock implementation. > > You _could_ use the linux test_and_set bitop, but those are defined on > unsigned long and spinlock_t is generally assumed to be of unsigned int > size. > > Go with the ticket locks as per below. Ok, I'll learn it. > > Ok, I'll try to implement ticket lock in next version patch. > > If you need inspiration, look at: > arch/arm/include/asm/spinlock.h > > Or look at the current version of that file and ignore the LSE version. > > Note that unlock is a store half-word (u16), not having seen your arch > manual yet I don't know if you even have that. Nice tips, thank you very much. Guo Ren