Re: large page patch (fwd) (fwd)

Daniel Phillips
2002-08-09T17:10:21Z

On Friday 09 August 2002 18:51, Linus Torvalds wrote:
> On Fri, 9 Aug 2002, Daniel Phillips wrote:
> > Slab allocations would not have GFP_DEFRAG (I mistakenly wrote GFP_LARGE
> > earlier) and so would be allocated outside ZONE_LARGE.
>
> .. at which poin tyou then get zone balancing problems.
>
> Or we end up with the same kind of special zone that we have _anyway_ in
> the current large-page patch, in which case the point of doing this is
> what?

The current large-page patch doesn't have any kind of defragmentation in the
special zone and that memory is just not available for other uses. The thing
is, when demand for large pages is low the zone should be allowed to fragment.

All of highmem also qualifies as defraggable memory, so certainly on these
big memory machines we can easily get a majority of memory in large pages.

I don't see a fundamental reason for new zone balancing problems. The fact
that balancing has sucked by tradition is not a fundamental reason ;-)

--
Daniel