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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 D2AEDC4361B for ; Wed, 9 Dec 2020 08:17:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D78323B99 for ; Wed, 9 Dec 2020 08:17:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726955AbgLIIR2 (ORCPT ); Wed, 9 Dec 2020 03:17:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725765AbgLIIRZ (ORCPT ); Wed, 9 Dec 2020 03:17:25 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B251C0613CF for ; Wed, 9 Dec 2020 00:16:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=7DbXicEP14682gFH5lbRgzIsZ1ZZPjA3ihyvb2YqmuY=; b=qWkGuRldOYs++JE0EgNIrR+fcB LIWr7c4fS2+kEFIWlRNvsvnyJLQToQqAUjMsU00zXGtx8Cc+UXUCaqcbJNUfQANibRI5MQFYROwZY S1Z6qAtleDO4qyyW1PtoMxa3qpeLPLXXb5stOEt29NFxcWVwsfwfQU8NLAZtn8bszr3G9y79VbQbC kzIW5LXtSlses9e3AJVkpkTyn3hiPdplROmkSPLahscqYNdd6fDrull9FdeS0Aaw/+mSCF/xDWJrs WKtBpwbiqpE00FCCtf6cMxLB0jk5P9oRtCzZzhiANRNQv4oBiBReyEoygDSpP+LrJvMcfLxOgWP7E wDG7Rg5A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmueA-0000ob-7I; Wed, 09 Dec 2020 08:16:27 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 7F4A830477A; Wed, 9 Dec 2020 09:16:23 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6748F200F8CC1; Wed, 9 Dec 2020 09:16:23 +0100 (CET) Date: Wed, 9 Dec 2020 09:16:23 +0100 From: Peter Zijlstra To: John Ogness Cc: Sergey Senozhatsky , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Linus Torvalds , Greg Kroah-Hartman , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH next v2 2/3] printk: change @clear_seq to atomic64_t Message-ID: <20201209081623.GI2414@hirez.programming.kicks-ass.net> References: <20201201205341.3871-1-john.ogness@linutronix.de> <20201201205341.3871-3-john.ogness@linutronix.de> <875z5c9bhn.fsf@jogness.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <875z5c9bhn.fsf@jogness.linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 08, 2020 at 11:36:44PM +0106, John Ogness wrote: > For the state variable we chose atomic_long_t instead of atomic64_t for > this reason. atomic_long_t operations are available atomically on all > architectures. Please put on your eye cancer gear and inspect the atomic implementation of PA-RISC, Sparc32, feh, I forgot who else. Those SMP capable architectures are gifted with just one XCHG like atomic instruction :/ Anyway, as said in the other email, they also don't have NMIs so it mostly works.