Re: why does the macro "ZERO_PAGE" take an argument?

[H. Peter Anvin]

Robert P. J. Day wrote:
>> The comment above empty_zero_page and zero_page_mask
>> declarations at arch/mips/mm/init.c:508 sheds light on this ...
> 
> well, it *sort of* does.  at line 64 of that file:
> 
> /*
>  * We have up to 8 empty zeroed pages so we can map one of the right colour
>  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
>  * where we have to avoid VCED / VECI exceptions for good performance at
>  * any price.  Since page is never written to after the initialization we
>  * don't have to care about aliases on other CPUs.
>  */
> 
> although it's not clear where in the source tree are the invocations
> that would actually make a difference to a MIPS system, which is why
> i've CC'ed ralf on this.  i'm sure he can clear this up. :-)

x86 could also benefit from coloured zeropages.  In fact, I thought it
already had them (K8 wants as many as 8.)

	-hpa
-
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/