Re: [PATCH] ppc32 copy_to_user dcbt fixup

[Bryan Rittmeyer]

On Sat, Mar 13, 2004 at 03:50:03PM +1100, Benjamin Herrenschmidt wrote:
> It would be wise to make the dcbz as long as possible in "advance"
> before the actual write to the cache line.

I guess we could try "pre-dcbz" ala the dcbt prefetch code.
Even dcbz right before stw is probably cheaper than RAM
loading data that will be totally overwritten. It's hard to
lose eliminating bus I/O (especially reads).

Any comments on the dcbt prefetch patch?

-Bryan

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/