Re: [PATCH] Reduce the number of expensive division instructions done by _parse_integer()

From: David Howells
Date: Thu Feb 09 2012 - 14:23:16 EST


Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> Btw, what was the load that you noticed this on?
>
> Because quite frankly, I think we only support bases 8/10/16 in the
> kernel, and if you really have some case where this all is expensive,
> it might be better to simply have three different functions for the
> three bases. That would turn the multiplies into constants too, and
> also simplify the character tests.
>
> That said, I can't really see how this could ever be all that hot a
> function. Did you ever see it in a profile, or was this all just from
> looking at the code?

Just by looking at the code. I can't think of anything particularly where
this is likely to be encountered in a critical path.

David
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