Re: [PATCH V5 0/4] Refactor do_wp_page, no functional change

[Andrew Morton <akpm@linux-foundation.org>]

On Sun, 22 Feb 2015 15:42:14 +0200 Shachar Raindel <raindel@mellanox.com> wrote:

> Currently do_wp_page contains 265 code lines. It also contains 9 goto
> statements, of which 5 are targeting labels which are not cleanup
> related. This makes the function extremely difficult to
> understand. The following patches are an attempt at breaking the
> function to its basic components, and making it easier to understand.
> 
> The patches are straight forward function extractions from
> do_wp_page. As we extract functions, we remove unneeded parameters and
> simplify the code as much as possible. However, the functionality is
> supposed to remain completely unchanged. The patches also attempt to
> document the functionality of each extracted function. In patch 2, we
> split the unlock logic to the contain logic relevant to specific needs
> of each use case, instead of having huge number of conditional
> decisions in a single unlock flow.

gcc-4.4.4:

   text    data     bss     dec     hex filename
  40898     186   13344   54428    d49c mm/memory.o-before
  41422     186   13456   55064    d718 mm/memory.o-after

gcc-4.8.2:

   text    data     bss     dec     hex filename
  35261   12118   13904   61283    ef63 mm/memory.o
  35646   12278   14032   61956    f204 mm/memory.o

The more recent compiler is more interesting but either way, that's a
somewhat disappointing increase in code size for refactoring of a
single function.

I had a brief poke around and couldn't find any obvious improvements
to make.

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