From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030663Ab2CNDBR (ORCPT ); Tue, 13 Mar 2012 23:01:17 -0400 Received: from perches-mx.perches.com ([206.117.179.246]:48400 "EHLO labridge.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1030539Ab2CNDBP (ORCPT ); Tue, 13 Mar 2012 23:01:15 -0400 Message-ID: <1331694074.27389.42.camel@joe2Laptop> Subject: Re: [PATCH] checkpatch: Suggest pr_ over printk(KERN_ From: Joe Perches To: "Ted Ts'o" Cc: Andrew Morton , Andy Whitcroft , LKML Date: Tue, 13 Mar 2012 20:01:14 -0700 In-Reply-To: <20120314024104.GE15379@thunk.org> References: <20120313120514.GA17538@thunk.org> <20120313145517.f4fcae46.akpm@linux-foundation.org> <20120313220144.GD11969@thunk.org> <20120313150316.6ae19b95.akpm@linux-foundation.org> <20120314003157.GA15379@thunk.org> <1331686026.24613.6.camel@joe2Laptop> <20120314010701.GB15379@thunk.org> <1331687831.27389.2.camel@joe2Laptop> <20120314021938.GD15379@thunk.org> <1331692311.27389.27.camel@joe2Laptop> <20120314024104.GE15379@thunk.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2012-03-13 at 22:41 -0400, Ted Ts'o wrote: > On Tue, Mar 13, 2012 at 07:31:51PM -0700, Joe Perches wrote: > > Right now many fs ext4 messages are somewhat opaque > > without any reference to what kernel subsystem produced > > the message. > > > > For instance: > > > > fs/ext4/ialloc.c: printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n", > > > > This is a somewhat senseless output in dmesg without > > any linkage to ext4. > > > > Using pr_fmt and pr_debug as I sent a patch to do > > instead emits in dmesg: > > > > EXT4-fs: group: etc... > > > > Using subsystem prefixes makes it easy and consistent to > > grep dmesg. > > That's a debug message which is never by anyone other than ext4 > developers. Your patch also hacked the Makefile to enable it by > default, It's just an example and no it didn't. That output is still in an #ifdef EXT4FS_DEBUG block and is unchanged. What I did was #define DEBUG so pr_debug (and so dynamic_debug if desired as well) emits output to dmesg. +ccflags-$(CONFIG_EXT4_FS) := -DDEBUG ext4 doesn't currently use any #ifdef DEBUG blocks. > which also enabled some performance degrading code paths > (again, only enabled by developers who manually drop the #define in a > header file when they are trying to figure out some obscure failure > during the development process). This is why I don't like people who > are wanking around in code they don't understand just to fix style > fixes, in the mistaken belief that it adds value. cheers, Joe