Re: MMX performance....

Robert Krawitz (
6 Feb 1997 23:10:40 GMT

In article <> Chris Evans <> writes:

On 6 Feb 1997, Robert Krawitz wrote:

> The Pentium memcpy() patch, BTW, has a lot of overhead of its own; it
> dumps and restores the FPU state (when it's in use it dumps the
> registers; when not, it dumps just the rest of the state). That's why
> it's configured to operate only when the amount of data to be copied
> is large. The overhead is well worth it, though, since memory
> bandwidth on write is used so much more efficiently.

Is the Pentium memcpy patch in 2.1.x yet? If not, why not? Such a low
level change should go into the development kernels as early as possible,

I've been sending it off to Linus periodically. He hasn't responded.
I would like to see it in the kernel.

Actually it's about time I started using development kernels on my
personal box. I like to always run with the memcpy patch though. Is there
at least a 2.1.x patch for it?

Please see my web page

Robert Krawitz <> 

Member of the League for Programming Freedom -- mail Tall Clubs International -- or 1-800-521-2512