Re: [PATCH 10/28] i386: map enough initial memory to create lowmem mappings

Jeremy Fitzhardinge
2007-04-25T21:31:23Z

Eric W. Biederman wrote:
> Jeremy did your kernel have PAE enabled?
>
> It just occurred to me that we have at all of the memory below 1M (say about
> 512K) mapped and available to setup new mappings.
>
> The only way I can see a page fault happening is if you were using a PAE
> enabled kernel (so you were not updating the current page tables) and
> you have more than 256M of low memory, and we don't get any much extra
> from always mapping 4M at a time.

Yes, that's the situation. PAE enabled, ~768MB of memory and a large
kernel which mostly fills the 8M mapping.

J