Re: [GIT PULL] MM updates for 6.5-rc1

[David Howells]

Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> Side note: I think we should just do the "FOLL_GET" doesn't touch the
> refcount either, which would make this all become just

Yeah... but there's a lot of places that would potentially need fixing.
iov_iter_get_pages*(), for example, is used to grab pages and push them to all
sorts of destinations, including pipes and sk_buffs.

> but then we would need to fix try_grab_page() and gup_put_folio() and
> friends to match. And any other cases I haven't thought of.

And put_page(), folio_put(), ...  I wonder if there would be a noticeable
performance loss from adding an is_zero_page() check into those.

It might also make sense to include the entire kernel post-init static image
in that, perhaps a check:

	if ((unsigned long)(virt_address) & KERNEL_MASK == KERNEL_BASE)
		return;

David