From: Joe Perches <joe@perches.com>
To: "Ted Ts'o" <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andy Whitcroft <apw@shadowen.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] checkpatch: Suggest pr_<level> over printk(KERN_<LEVEL>
Date: Tue, 13 Mar 2012 20:01:14 -0700 [thread overview]
Message-ID: <1331694074.27389.42.camel@joe2Laptop> (raw)
In-Reply-To: <20120314024104.GE15379@thunk.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
next prev parent reply other threads:[~2012-03-14 3:01 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120302025554.GA13493@joana>
[not found] ` <20120301.221643.881299898523907213.davem@davemloft.net>
[not found] ` <20120301.222316.1877216960521396397.davem@davemloft.net>
[not found] ` <20120301.222604.1508242694024394849.davem@davemloft.net>
[not found] ` <1330661602.1939.13.camel@joe2Laptop>
2012-03-02 5:35 ` [PATCH] checkpatch: Add --strict tests for braces, comments and casts Joe Perches
2012-03-02 5:54 ` [PATCH] checkpatch: Add --strict test for strings split across multiple lines Joe Perches
2012-03-13 6:23 ` [PATCH] checkpatch: Suggest pr_<level> over printk(KERN_<LEVEL> Joe Perches
2012-03-13 12:05 ` Ted Ts'o
2012-03-13 21:55 ` Andrew Morton
2012-03-13 22:01 ` Ted Ts'o
2012-03-13 22:03 ` Andrew Morton
2012-03-14 0:31 ` Ted Ts'o
2012-03-14 0:47 ` Joe Perches
2012-03-14 1:07 ` Ted Ts'o
2012-03-14 1:17 ` Joe Perches
2012-03-14 2:19 ` Ted Ts'o
2012-03-14 2:31 ` Joe Perches
2012-03-14 2:41 ` Ted Ts'o
2012-03-14 3:01 ` Joe Perches [this message]
2012-03-14 12:34 ` Ted Ts'o
2012-03-14 13:05 ` Joe Perches
2012-03-14 13:45 ` Ted Ts'o
2012-03-14 14:06 ` Joe Perches
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