CONFIG_CGROUP_WRITEBACK=y/n complexity (was: Re: Build regressions/improvements in v4.3-rc7)

From: Geert Uytterhoeven
Date: Sun Oct 25 2015 - 06:54:43 EST


On Sun, Oct 25, 2015 at 11:12 AM, Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> wrote:
> Below is the list of build error/warning regressions/improvements in
> v4.3-rc7[1] compared to v4.2[2].
>
> Summarized:
> - build errors: +13/-8
> - build warnings: +160/-100
>
> JFYI, when comparing v4.3-rc7[1] to v4.3-rc6[3], the summaries are:
> - build errors: +12/-4
> - build warnings: +42/-40

> [1] http://kisskb.ellerman.id.au/kisskb/head/9511/ (256 out of 254 configs)
> [2] http://kisskb.ellerman.id.au/kisskb/head/9309/ (all 254 configs)
> [3] http://kisskb.ellerman.id.au/kisskb/head/9487/ (255 out of 254 configs)

> *** WARNINGS ***
>
> 160 regressions:

> + /home/kisskb/slave/src/mm/page-writeback.c: warning: 'filepages' is used uninitialized in this function: => 1582, 1908
> + /home/kisskb/slave/src/mm/page-writeback.c: warning: 'headroom' is used uninitialized in this function: => 1582, 1908

Please refactor this code. It falls under the "so complicated that there are
no obvious deficiencies " category
(https://en.wikiquote.org/wiki/C._A._R._Hoare).

Thanks a lot!

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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