Re: [PATCH] Convert pgtable cache to slab

Robin Holt
2005-02-15T19:59:45Z

On Tue, Feb 15, 2005 at 11:46:21AM -0800, David Mosberger wrote:
> >>>>> On Tue, 15 Feb 2005 13:31:48 -0600, Robin Holt <holt@sgi.com> said:
>
> Robin> Is there a strong objection to implementing 4 levels of 16k
> Robin> page tables for now and then, if someone else sees a need,
> Robin> convert to using long page table format and adjust page
> Robin> tables as needed at that point in time.
>
> I certainly don't want to switch my machines to 4-levels. There is
> zero need for that on the machines I use, so why pay the overhead of
> an extra level?

I missed the why the extra level question. That part is motivated by
some large MPI jobs need a fourth level to get a large enough single
mapping to cover their entire dataset. We have already tripped this
limitation for a couple of our really large customers.

Thanks,
Robin