Re: [QUICKLIST 1/4] Quicklists for page table pages V5

Benjamin Herrenschmidt
2007-04-10T04:45:37Z

On Mon, 2007-04-09 at 11:25 -0700, Christoph Lameter wrote:

> Quicklists for page table pages V5

Looks interesting, but unfortunately not very useful at this point for
powerpc unless you remove the assumption that quicklists contain
pages...

On powerpc, we currently use kmem cache slabs (though that isn't
terribly node friendly) whose sizes depend on the page size.

For a 4K page size kernel, we have 4 level page tables and use 2 caches,
PTE and PGD pages are 4K (thus are PAGE_SIZE'd), and PMD & PUD are 1K.

For a 64K page size kernel, we have 3 level page tables and we use 3
caches: a PGD pages are 128 bytes (yeah, not big heh...), our pmd
pages are 32K (half a page) and PTE pages are PAGE_SIZE (64K).

Cheers,
Ben.