Re: uaccess.h reimplementation, patch, 2.1.30

Ingo Molnar (mingo@pc5829.hil.siemens.at)
Tue, 1 Apr 1997 11:54:42 +0200 (MET DST)


On Mon, 31 Mar 1997, Paul Gortmaker wrote:

> > I'm curious wether the speed/size+cache locality improvement seen by Paul
> > Gortmaker stands for this implementation too.
>
> Okay, as soon as I saw Linus mention the broken WP support, I realized why
> defining access_ok() to 1 was such a gain on i386. [...]

duh for some reason i thought it was an i486.

The code should make the least difference on an i486: no segment
descriptor cache, no branch predicion (which could go wrong), no
aggressive prefetching.

i think if there is any difference visible in macro-benchmarks, then on
P5-s.

-- mingo