Hi,
On Thu, May 11, 2023 at 03:02:55PM +0100, Matthew Wilcox wrote:
On Wed, May 10, 2023 at 09:35:44PM -0700, Hugh Dickins wrote:
On Wed, 10 May 2023, Matthew Wilcox wrote:
I don't really understand why you're going down a remove-CONFIG_HIGHPTE
route: I thought you were motivated by the awkardness of kmap on large
folios; but I don't see how removing HIGHPTE helps with that at all
(unless you have a "large page tables" effort in mind, but I doubt it).
Quite right, my primary concern is filesystem metadata; primarily
directories as I don't think anybody has ever supported symlinks or
superblocks larger than 4kB.
I was thinking that removing CONFIG_HIGHPTE might simplify the page
fault handling path a little, but now I've looked at it some more, and
I'm not sure there's any simplification to be had. It should probably
use kmap_local instead of kmap_atomic(), though.
Removing CONFIG_HIGHPTE will drop several lines and will allow to get rid
of custom __pte_alloc_one on x86.
--
Sincerely yours,
Mike.
