Re: sparsemem & sparsemem extreme question

Dave Hansen
2005-10-05T16:03:04Z

On Wed, 2005-10-05 at 17:58 +0200, Heiko Carstens wrote:
> we have the 1:1 mapping already
> today. So adding anything to the vmalloc area won't make it more expensive.

The pagetables themselves have a cost, as do the lookups. Those make it
more expensive. On 64-bit machines the vaddr space is not an expense.

> No, my concern is actually that the s390 archticture actually will come up
> with some sort of memory that's present in the physical address space where
> the most significant bit of the addresses will be turned _on_.

Why do you think this?

-- Dave