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=-7.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 038B4C433E0 for ; Mon, 27 Jul 2020 08:53:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D106A20719 for ; Mon, 27 Jul 2020 08:53:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oNt5D6E0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726885AbgG0Ixr (ORCPT ); Mon, 27 Jul 2020 04:53:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726800AbgG0Ixq (ORCPT ); Mon, 27 Jul 2020 04:53:46 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F7D8C061794 for ; Mon, 27 Jul 2020 01:53:46 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id a9so8901922pjd.3 for ; Mon, 27 Jul 2020 01:53:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=dlbk2wv3IwbKr19nsqbGp2cZk7iHJ7ID8YfsZ80+he0=; b=oNt5D6E01AoIzbc4pvn57XvzmtTWDWJ6t2DuiJFoyey0DfLT/XPVmpnSpqaZsiEH4m MuARdtorq63WDmi3Cg7BON2satHovIUoaO75IJNdEkPjYIXL/b33r23C34sUFR3zHRRT 4ijvagufLooaKwPBBJh9tem09s4YAmMLnw5zhfckxgwQA3Rdwy0ekwhOa38xK1Yl4K1U hhD08livvjTmYhXwDa8otIdPHAT0nnf8OyZkIWPVNfK3xmQPziZrmFpyAvr6B1s8nO6W KWP3kNLxydVtOfIYGSPfmbb/eGRJW9puKFLwAmYxReBzJMwQy3gckH+8swF6zs325zjP Pprg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=dlbk2wv3IwbKr19nsqbGp2cZk7iHJ7ID8YfsZ80+he0=; b=pdOkxpErOEgXqRXgAQkdZUBBIBFkoUFpxNaIuSOhdbxy510o1ZcVc16KjcvMiKXONg mJDo6mgGwMQPWC+36VtKkLDeBNpOl47UkyG16zSwv06IWYXMBbE4BGsCO2DfOOGD4Emp qJGXrpDo1oQ8GJaWjgJww+iKkjhczLq9lhjKfVu35ETjkfYNKpszAcsoqVHzm+e8zPHn Q3gcDGb/mbpoJw85yUuziTR5TXmiL/JPdA7rZdGQTpDNJxQw7ZOBXXg4rK8PO1r+lFll +SV7ZG2caHB0NylPeIXJtR8ccsASbvlEsRB5GMzxHx/hm0fwQh5+IRT/UwvM3Fu3DBBN ytdQ== X-Gm-Message-State: AOAM533/+t7AMZUTTgCTSbnWF0wCYXBqoireJSMdp0RtYEWNS5B0btWb gmUA5C2ih4ObxyBh35XwUAY= X-Google-Smtp-Source: ABdhPJw9ONJW+8Y7CSU3U+NA09a/iAa0fYex9PRdJYd9hn+45tASoAqKdztcxPiG7qEzOKHBySa4gQ== X-Received: by 2002:a17:90a:6acb:: with SMTP id b11mr17506051pjm.71.1595840026121; Mon, 27 Jul 2020 01:53:46 -0700 (PDT) Received: from localhost ([2409:10:2e40:5100:6e29:95ff:fe2d:8f34]) by smtp.gmail.com with ESMTPSA id br9sm13200664pjb.56.2020.07.27.01.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jul 2020 01:53:45 -0700 (PDT) Date: Mon, 27 Jul 2020 17:53:43 +0900 From: Sergey Senozhatsky To: John Ogness Cc: Petr Mladek , Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , Linus Torvalds , Greg Kroah-Hartman , Peter Zijlstra , Thomas Gleixner , Marco Elver , kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2][next] printk: ringbuffer: support dataless records Message-ID: <20200727085343.GF1386@jagdpanzerIV.localdomain> References: <20200721132528.9661-1-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200721132528.9661-1-john.ogness@linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (20/07/21 15:31), John Ogness wrote: > With commit ("printk: use the lockless ringbuffer"), printk() > started silently dropping messages without text because such > records are not supported by the new printk ringbuffer. > > Add support for such records. > > Currently dataless records are denoted by INVALID_LPOS in order > to recognize failed prb_reserve() calls. Change the ringbuffer > to instead use two different identifiers (FAILED_LPOS and > NO_LPOS) to distinguish between failed prb_reserve() records and > successful dataless records, respectively. > > Fixes: ("printk: use the lockless ringbuffer") > Fixes: https://lkml.kernel.org/r/20200718121053.GA691245@elver.google.com > Reported-by: Marco Elver > Signed-off-by: John Ogness Applied to printk-rework, thanks. -ss