On Mon, Oct 21, 2024 at 04:33:19PM +0100, Lorenzo Stoakes wrote: [snip] > * For hardware poison markers it makes sense to drop them as you're > effectively saying 'I am done with this range that is now unbacked and > expect to get an empty page should I use it now'. UFFD WP I am not sure > about but presumably also fine. [snip] CORRECTION: (sorry multitasking atm now I have a non-melted CPU) UFFD WP is safe from MADV_FREE as it checks is_poisoned_swp_entry() which this patch updates to include guard pages, a change I will undo in v3. So disregard comment on UFFD WP here.