On Mon, 2012-03-19 at 18:28 -0700, david@lang.hm wrote:

On Mon, 19 Mar 2012, Ted Ts'o wrote:

quoted

On Mon, Mar 19, 2012 at 10:44:10AM -0700, Joe Perches wrote:

quoted

This stuff ain't whitespace.

quoted

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