From: Joe Perches <joe@perches.com>
To: david@lang.hm
Cc: Ted Ts'o <tytso@mit.edu>,
Valdis.Kletnieks@vt.edu, Jiri Slaby <jirislaby@gmail.com>,
Andreas Dilger <adilger.kernel@dilger.ca>,
linux-ext4@vger.kernel.org,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/9] ext4: Use pr_fmt and pr_<level>
Date: Mon, 19 Mar 2012 18:51:12 -0700 [thread overview]
Message-ID: <1332208272.7847.39.camel@joe2Laptop> (raw)
In-Reply-To: <alpine.DEB.2.02.1203191826100.22704@asgard.lang.hm>
On Mon, 2012-03-19 at 18:28 -0700, david@lang.hm wrote:
> On Mon, 19 Mar 2012, Ted Ts'o wrote:
> > On Mon, Mar 19, 2012 at 10:44:10AM -0700, Joe Perches wrote:
> >> This stuff ain't whitespace.
> >>> I'll have to respectfully disagree with you. For ext4, as far as I am
> > concerned, changing printk(KERN_INFO, ...) to pr_info(...) is *purely*
> > a whitespace-level change.
> Joe, if everything did change, what difference would it make?
Hi David.
> just being a consistant style doesn't matter much,
Perhaps we disagree on the value of consistency.
I believe it's a small but measurable effect and it
can reduce overall ongoing defect rates.
Is it DoublePlus_important_? No, definitely not.
To me using pr_<level> is a bit like using const
or marking sections devinitconst.
It hardly matters, but it's good form and it can
free up some working memory in ram limited systems.
> but if there is some
> functionality that would be possible with pr_info(...) that would not be
> possible with printk(KERN_INFO, ...), there may be more reason to change.
Right now, it's just macros over printk so it's pretty
trivial. I do intend to convert pr_<level> macros to
functions eventually to reduce code size ~.5% overall.
That reduction does depend on quantity of CONFIG_<FOO>
options enabled of course. Enable everything, I think
it's ~.01%. I haven't done it in quite awhile though
so that's a guess.
It matters a tiny bit more for flash or ram limited
systems.
Some driver optimizations like the rtlwifi reduction
in -next commit 481b9606ec might have more of an
impact though for those systems.
So, it depends...
cheers, Joe
next prev parent reply other threads:[~2012-03-20 1:51 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-16 0:07 [PATCH 0/9] ext4: Message logging corrections and neatening Joe Perches
2012-03-16 0:07 ` [PATCH 1/9] ext4: Add -DDEBUG to Makefile Joe Perches
2012-03-16 16:03 ` David Daney
2012-03-16 16:29 ` Joe Perches
2012-03-19 4:39 ` Ted Ts'o
2012-03-19 16:26 ` Joe Perches
2012-03-19 18:48 ` David Daney
2012-03-20 1:05 ` Ted Ts'o
2012-03-16 0:07 ` [PATCH 2/9] ext4: Use pr_fmt and pr_<level> Joe Perches
2012-03-19 4:09 ` Ted Ts'o
2012-03-19 4:14 ` David Miller
2012-03-19 4:34 ` Ted Ts'o
2012-03-19 5:12 ` David Miller
2012-03-19 15:31 ` Ted Ts'o
2012-03-19 15:51 ` Anca Emanuel
2012-03-19 16:14 ` Joe Perches
2012-03-19 16:14 ` Ted Ts'o
2012-03-19 18:14 ` David Miller
2012-03-19 18:31 ` Ted Ts'o
2012-03-19 18:46 ` Joe Perches
2012-03-20 1:04 ` Ted Ts'o
2012-03-20 1:33 ` Joe Perches
2012-03-20 1:47 ` Ted Ts'o
2012-03-20 1:59 ` Joe Perches
2012-03-20 2:58 ` Ted Ts'o
2012-03-20 3:02 ` Joe Perches
2012-03-20 5:46 ` Valdis.Kletnieks
2012-03-20 7:10 ` David Miller
2012-03-20 8:47 ` Jiri Slaby
2012-03-20 9:44 ` Joe Perches
2012-03-20 9:27 ` Geert Uytterhoeven
2012-03-20 13:03 ` Ted Ts'o
2012-03-20 18:47 ` Valdis.Kletnieks
2012-03-20 1:46 ` Al Viro
2012-03-19 17:53 ` David Miller
2012-03-19 4:25 ` Joe Perches
2012-03-19 4:36 ` Ted Ts'o
2012-03-19 16:46 ` Jiri Slaby
2012-03-19 17:09 ` Joe Perches
2012-03-19 17:36 ` Valdis.Kletnieks
2012-03-19 17:44 ` Joe Perches
2012-03-20 1:06 ` Ted Ts'o
2012-03-20 1:28 ` david
2012-03-20 1:51 ` Joe Perches [this message]
2012-03-20 1:33 ` Joe Perches
2012-03-20 8:57 ` Jiri Slaby
2012-03-20 9:21 ` Joe Perches
2012-03-20 9:25 ` Jiri Slaby
2012-03-20 9:46 ` Joe Perches
2012-03-22 17:02 ` Jiri Slaby
2012-03-22 17:42 ` Joe Perches
2012-03-19 4:55 ` Ted Ts'o
2012-03-19 5:13 ` David Miller
2012-03-19 5:39 ` Joe Perches
2012-03-16 0:07 ` [PATCH 3/9] ext4: Fix indentation Joe Perches
2012-03-19 4:10 ` Ted Ts'o
2012-03-19 4:30 ` Joe Perches
2012-03-16 0:07 ` [PATCH 4/9] ext4: Add no_printk argument validation, fix fallout Joe Perches
2012-03-19 4:16 ` Ted Ts'o
2012-03-16 0:07 ` [PATCH 5/9] ext4: Avoid output message interleaving in ext4_error_<foo> Joe Perches
2012-03-19 4:51 ` Ted Ts'o
2012-03-16 0:07 ` [PATCH 6/9] ext4: Remove redundant "EXT4-fs: " from uses of ext4_msg Joe Perches
2012-03-19 4:13 ` Ted Ts'o
2012-03-16 0:07 ` [PATCH 7/9] ext4: Format neatening for easier grep Joe Perches
2012-03-19 4:26 ` Ted Ts'o
2012-03-19 4:30 ` Joe Perches
2012-03-16 0:07 ` [PATCH 8/9] ext4: Neaten ext4_error uses Joe Perches
2012-03-16 0:07 ` [PATCH 9/9] ext4: Rename ext4_warning to ext4_warn and ext4_error to ext4_err Joe Perches
2012-03-19 4:51 ` Ted Ts'o
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