From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754156AbZJERWb (ORCPT ); Mon, 5 Oct 2009 13:22:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753596AbZJERWa (ORCPT ); Mon, 5 Oct 2009 13:22:30 -0400 Received: from mail.perches.com ([173.55.12.10]:1852 "EHLO mail.perches.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753480AbZJERWa (ORCPT ); Mon, 5 Oct 2009 13:22:30 -0400 Subject: Re: [PATCH 02/21] ftrace.c: Add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt From: Joe Perches To: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org, Frederic Weisbecker , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org In-Reply-To: <1254748256.13160.0.camel@gandalf.stny.rr.com> References: <9b377eefae9e28c599dd4a17bdc81172965e9931.1254701151.git.joe@perches.com> <1254748256.13160.0.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 05 Oct 2009 10:21:52 -0700 Message-Id: <1254763312.1799.507.camel@Joe-Laptop.home> Mime-Version: 1.0 X-Mailer: Evolution 2.28.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2009-10-05 at 09:10 -0400, Steven Rostedt wrote: > On Sun, 2009-10-04 at 17:53 -0700, Joe Perches wrote: > > Remove prefixes from pr_, use pr_fmt(fmt) > > No change in output. > What does KBUILD_MODNAME give us in the core code? This file does not > belong to any module and is only compiled into the core kernel. Hi Steven. KBUILD_MODNAME is basename(__FILE__), or if multiple files are grouped in the Makefile, then it's the basename(group) http://lkml.indiana.edu/hypermail/linux/kernel/0210.2/0325.html For ftrace.c, it gives "ftrace", which is the same as the prefix you were using, so there's no change in the output. For other entries in say kernel/power, there were messages that did not have prefixes I believe these are some of the +/-'s of each approach: Current: o Allows some messages to not have a prefix at all o Prefixes can vary inside a specific compilation unit Proposed: o Consistent, smaller source code, with no typos for instance: acpi/apic typos were found/fixed kernel/power had messages without PM: mce used "MCE: " and "mce: " prefixes o Compatible with KMSG_COMPONENT o All logging messages should have a prefix so it could be easier to grep/categorize logs o Future: - Doesn't require each compilation unit to #define pr_fmt - Smaller objects without duplicated prefixes - Extensible via some dynamic_debug like mechanism to hide or show modname/__func__/offset without significant overhead or any increase in object size (printk would emit the prefix via some insertion mechanism after "") cheers, Joe