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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, 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 82346C43387 for ; Tue, 18 Dec 2018 17:47:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5308221873 for ; Tue, 18 Dec 2018 17:47:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="aZHPdKxR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727400AbeLRRrb (ORCPT ); Tue, 18 Dec 2018 12:47:31 -0500 Received: from mail.skyhub.de ([5.9.137.197]:41940 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726659AbeLRRra (ORCPT ); Tue, 18 Dec 2018 12:47:30 -0500 Received: from zn.tnic (p200300EC2BD1780024767CD486D27DCB.dip0.t-ipconnect.de [IPv6:2003:ec:2bd1:7800:2476:7cd4:86d2:7dcb]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id C0AF51EC0AC4; Tue, 18 Dec 2018 18:47:28 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1545155248; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=J9FtZd02FqpcwI3gCnC/QIS1vF5PhX7bNJRnD+aEa20=; b=aZHPdKxRYCvJFhywkbzutl2ZneAkhj8mHTfaDnoDIlEt/b88qqOAqg+eEqXHOkc9SBXTBf n/hiMrefT5JCOceKUEoGNx3xq8HV8P605jhkcp9xtYXWNmJKMLrFcEIDT0QJYgFeUHePoW G5lVhQ/fEDlD3GZelESEynmVGXFFJOc= Date: Tue, 18 Dec 2018 18:47:23 +0100 From: Borislav Petkov To: Sergey Senozhatsky Cc: Sergey Senozhatsky , Peter Zijlstra , Petr Mladek , Steven Rostedt , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH] printk: increase devkmsg write() ratelimit Message-ID: <20181218174723.GK7485@zn.tnic> References: <20181218104812.GC15430@hirez.programming.kicks-ass.net> <20181218111701.GA32522@jagdpanzerIV> <20181218114709.GF7485@zn.tnic> <20181218130750.GA665@tigerII.localdomain> <20181218142623.GH7485@zn.tnic> <20181218145558.GD665@tigerII.localdomain> <20181218150313.GI7485@zn.tnic> <20181218151455.GE665@tigerII.localdomain> <20181218152413.GJ7485@zn.tnic> <20181218165217.GA534@tigerII.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181218165217.GA534@tigerII.localdomain> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 19, 2018 at 01:52:17AM +0900, Sergey Senozhatsky wrote: > But devkmsg ratelimits systemd errors, so one does not even know that > "some debugging is required". For instance from my x86 box: > > Unmounting /home... > [..] > home.mount: Mount process exited, code=exited status=32 > Failed unmounting /home. > > I don't want to debug systemd, I want to know that something didn't > work out. 10 messages max and 5 seconds interval looks a bit too strict. So how much is not strict? And what happens if you raise that ratelimiting level and the *one* line which is most important for debugging an issue, still doesn't get logged because all of a sudden, doofus is more talkative, overflows the new limit and we drop the important line? All I'm saying is, gradually raising the limit is the wrong approach - there will always be a case where something important doesn't get logged. What we need is a different solution, maybe what Rostedt proposes or so... -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.