linux-kernel - Re: [PATCH 1/3] mm: page_alloc: Reduce object size by neatening printks

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Message-ID: <20170317073943.GA26298@dhcp22.suse.cz>
Date:   Fri, 17 Mar 2017 08:39:44 +0100
From:   Michal Hocko <mhocko@...nel.org>
To:     Joe Perches <joe@...ches.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 1/3] mm: page_alloc: Reduce object size by neatening
 printks

On Thu 16-03-17 13:32:23, Joe Perches wrote:
> On Thu, 2017-03-16 at 11:56 +0100, Michal Hocko wrote:
> > On Wed 15-03-17 18:43:13, Joe Perches wrote:
> > > Function calls with large argument counts cause x86-64 register
> > > spilling.  Reducing the number of arguments in a multi-line printk
> > > by converting to multiple printks which saves some object code size.
> > > 
> > > $ size mm/page_alloc.o* (defconfig)
> > >    text    data     bss     dec     hex filename
> > >   35914	   1699	    628	  38241	   9561	mm/page_alloc.o.new
> > >   36018    1699     628   38345    95c9 mm/page_alloc.o.old
> > > 
> > > Miscellanea:
> > > 
> > > o Remove line leading spaces from the formerly multi-line printks
> > >   commit a25700a53f71 ("mm: show bounce pages in oom killer output")
> > >   back in 2007 started the leading space when a single long line
> > >   was split into multiple lines but the leading space was likely
> > >   mistakenly kept and subsequent commits followed suit.
> > > o Align arguments in a few more printks
> > 
> > This is really hard to review. Could you just drop all the whitespace
> > changes please?
> 
> It's a single, simple change. 

no it adds a lot of whitespace noise to an actual change. It takes to
check every single line to see whether some typo or unintended change
has been made.

> It's IMO trivial to review.

it's not IMNSHO.
-- 
Michal Hocko
SUSE Labs