From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754695AbYIQT1X (ORCPT ); Wed, 17 Sep 2008 15:27:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752848AbYIQT0v (ORCPT ); Wed, 17 Sep 2008 15:26:51 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42319 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752411AbYIQT0t (ORCPT ); Wed, 17 Sep 2008 15:26:49 -0400 Message-ID: <48D159A7.5080907@zytor.com> Date: Wed, 17 Sep 2008 12:25:27 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Jason Baron CC: Ingo Molnar , Andrew Morton , Yinghai Lu , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/6] loglevel=pci:8,acpi:8,apic=8 support v6 References: <1221640067-24389-1-git-send-email-yhlu.kernel@gmail.com> <20080917015543.27172da4.akpm@linux-foundation.org> <20080917092732.GB32107@elte.hu> <20080917184618.GB6486@redhat.com> In-Reply-To: <20080917184618.GB6486@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jason Baron wrote: > > hi, > > indeed both proposals seem to be addressing a similar core issue - being > able to dynamically (as opposed to re-compiling) change the amount of > verbosity that the kernel spews. I would liken it to adding a -verbose > flag to the kernel. > > Beyond that the 2 approaches differ in a number of ways as I see: > 8) The ability to accessed filtered messages a posteori (via dmesg), which is something we currently take for granted. This *is* the fundamental difference between what Yinghai has now and both your stuff and Yinghai's original proposal. Not producing the additional messages at all is inherently cheaper, sometimes *much* cheaper, but it obviously means the information is not accessible at all. At the moment, I would argue that the fact that dmesg is, in effect, more verbose than the kernel itself is a good thing; it makes dmesg dumps more useful. -hpa