RE: Uncached memory allocator for ia64.

Luck, Tony
2004-09-23T22:12:40Z

>I am not sure what will be acceptable at this point. Should I write
>an uncached allocator which grabs the granules at boot time before they
>are ever initialized for cacheable use? If so, would it be acceptable
>to just shrink each efi memory map entry by a command line specified
>size during the efi_memmap_walk callout? At this point I am so vague
>on what I should be doing that I am afraid to do much of anything.

We already make adjustments to the efi memory map (to trim sections to
granule boundaries) ... but another hack on top of the layers of ugliness
there already is going to make things worse. Perhaps someday we can
delete it all and start over.

Grabbing your memory out of the map before any of the rest of Linux
ever sees it sounds to be a good idea ... it avoids wasting memory
for page structures in mem_map that can only get you into trouble
if anyone ever looks at them.

If your allocator only needs a small number of pages from each node, then
it is possible that you'd be able to feed it the trimmed off scraps
from incomplete granules, rather than pull a whole granule. So you
might want to run your scan through the efi map before anyone else
messes with it.

-Tony