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.
