Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751658Ab3CAPIP (ORCPT ); Fri, 1 Mar 2013 10:08:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42960 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751060Ab3CAPIO (ORCPT ); Fri, 1 Mar 2013 10:08:14 -0500 From: Jeff Moyer To: Borislav Petkov Cc: Joern Engel , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH 3/9] printk: add CON_ALLDATA console flag References: <1362087602-8979-1-git-send-email-joern@logfs.org> <1362087602-8979-4-git-send-email-joern@logfs.org> <20130301145805.GC30938@pd.tnic> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Fri, 01 Mar 2013 10:08:00 -0500 In-Reply-To: <20130301145805.GC30938@pd.tnic> (Borislav Petkov's message of "Fri, 1 Mar 2013 15:58:06 +0100") Message-ID: User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1496 Lines: 33 Borislav Petkov writes: > On Fri, Mar 01, 2013 at 09:52:27AM -0500, Jeff Moyer wrote: >> > For consoles like netconsole and blockconsole the loglevel filtering >> > really doesn't make any sense. If a line gets printed at all, please >> > send it down to that console, no questions asked. >> >> Could you please explain this a bit further? Why wouldn't you want to >> allow the admin to filter log messages to the block or network console? >> This doesn't make a whole lot of sense to me, and in fact could cause >> problems for netconsole now that you're potentially sending a ton more >> traffic over the wire. > > Let's reverse the question: why would the admin ever want to filter > messages to debugging consoles like netconsole or blockconsole? > > When running a debugging session, you generally want to see *all* > messages. People don't just use this for "debugging sessions." They use it in production, and I already gave you one reason why you might not want to do this with netconsole (udp is unreliable, and I've definitely seem cases where netconsole suffered due to dropped packets; this won't make that better, especially when you multiply the extra bytes times the number of servers on the subnet). Cheers, Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/