Received: by 2002:a05:7412:8d10:b0:f3:1519:9f41 with SMTP id bj16csp4297728rdb; Mon, 11 Dec 2023 15:13:37 -0800 (PST) X-Google-Smtp-Source: AGHT+IH+bPbhFf0fG5xvNfTQx2lEczt31I4NFOhRFOL9WXYVGhtJ+mhvkXy0ZiXz8IgDqPlZAKnj X-Received: by 2002:a17:902:c943:b0:1d0:acd4:92ee with SMTP id i3-20020a170902c94300b001d0acd492eemr2954027pla.43.1702336417605; Mon, 11 Dec 2023 15:13:37 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1702336417; cv=none; d=google.com; s=arc-20160816; b=O04IuwNjeKBA0tzYH8moxp+23hhm15Pa+6rrYRGuuu5ElQ3QqSN3Jtrs02njam5xx7 UplDWSQG/b0aFBDpeRhNFBD7+Zq7Jd1n5G8zp/2jA1OknFaMEJRWL4xWfOQ27pScdj0R mZCLmp0dG2vPdjQrwtD0c5s0PLIt9EPDr1wN4JJSJp76N2qYMZY3gvYN99TVoPJgenTb KgBJ1ImyjJ0PrWYI9pYzC9XK6H75bB+PU6E0kt/A5KAz7iq6KsEccJG3RZFqUiTt7I4k 4cY7prswHiyaZKQOGVJcNCAOx7als+AitrmWWjbZeVUX30Pm1FfzleZJnngScGCVJC8c 2bjA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=YPQgxHMwRUsex8y7l77VrUgp0VRv4P5e2cM2ecCCPAo=; fh=0mCfkHQ5regzB63hJyl78nAkhqJvO03nWTTPqE+/JLk=; b=xDlQN4tfeJHN2UMJYKK77PRx/sQxzYIFo/2HFhuU0T9lzg6ybboiAZQm7nWhzFpU+k /+NVenB7hWnSWMns/20DQxLAx3pyQoSz+SE4/YZZ2HoIMbzLb0riv13s/xqN+P1rC/ZV Ni93iuDDLG0Qz40qJtjy8HmZiiZVyLHR/Uh1apE/CEwY2GdRsrz1euuQTOHeWOYIu+9h x+MI32bNk2L9xovV9JuV+Nj81uAkTHOcQuwUfzB74myzZiTKefkUT+//hBeG+kKeG6fr NRWPrPRPQP53nIE0/IX32RCJaho3wsUn5Ty/vAd7O4yOzQzOHYSHdHs2b03ZBbKkc3Od RfLA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from morse.vger.email (morse.vger.email. [23.128.96.31]) by mx.google.com with ESMTPS id x12-20020a1709029a4c00b001d0afa2f5e0si6701426plv.530.2023.12.11.15.13.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Dec 2023 15:13:37 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) client-ip=23.128.96.31; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by morse.vger.email (Postfix) with ESMTP id EF6CC807867C; Mon, 11 Dec 2023 15:13:34 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at morse.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345260AbjLKXNH (ORCPT + 99 others); Mon, 11 Dec 2023 18:13:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57636 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345166AbjLKXNG (ORCPT ); Mon, 11 Dec 2023 18:13:06 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 858119A for ; Mon, 11 Dec 2023 15:13:13 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 904BFC433C8; Mon, 11 Dec 2023 23:13:12 +0000 (UTC) Date: Mon, 11 Dec 2023 18:13:52 -0500 From: Steven Rostedt To: Mathieu Desnoyers Cc: linux-kernel@vger.kernel.org, Masami Hiramatsu , linux-trace-kernel@vger.kernel.org Subject: Re: [RFC PATCH] ring-buffer: Fix and comment ring buffer rb_time functions on 32-bit Message-ID: <20231211181352.088aeef5@gandalf.local.home> In-Reply-To: <20231211175904.29e01e8b@gandalf.local.home> References: <20231211201324.652870-1-mathieu.desnoyers@efficios.com> <20231211175904.29e01e8b@gandalf.local.home> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on morse.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (morse.vger.email [0.0.0.0]); Mon, 11 Dec 2023 15:13:35 -0800 (PST) On Mon, 11 Dec 2023 17:59:04 -0500 Steven Rostedt wrote: > > > > - A cmpxchg interrupted by 4 writes or cmpxchg overflows the counter > > and produces corrupted time stamps. This is _not_ fixed by this patch. > > Except that it's not 4 bits that is compared, but 32 bits. That should be "not 2 bits", as in "shave and a hair cut!" ;-) -- Steve