Re: find_new_bit bloat from x86 tree...

Ingo Molnar
2008-04-27T20:41:56Z

* David Miller <davem@davemloft.net> wrote:

> Ingo, what the heck is this?
>
> commit 64970b68d2b3ed32b964b0b30b1b98518fde388e
> Author: Alexander van Heukelum <heukelum@mailshack.com>

(Alexander Cc:-ed.)

> Date: Tue Mar 11 16:17:19 2008 +0100
>
> x86, generic: optimize find_next_(zero_)bit for small constant-size bitmaps
>
> Thanks for bloating up the inline expansion of this thing on every
> architecture that doesn't do __ffs() in a simple sequence of a few
> instructions like x86 does.

ok, that's bad. How much is the before/after vmlinux btw, i guess you
measured it? We could either make it per arch selectable, or we could
just uninline it all. It shouldnt be a big deal on x86 and it should
help on RISC platforms.

Ingo