Re: [PATCH 3/3] mm/devmap: Remove pgmap accounting in the get_user_pages_fast() path

On Thu, Mar 25, 2021 at 7:34 AM Jason Gunthorpe [off-list ref] wrote:

On Thu, Mar 18, 2021 at 10:03:06AM -0700, Dan Williams wrote:

quoted

Yes. I still need to answer the question of whether mapping
invalidation triggers longterm pin holders to relinquish their hold,
but that's a problem regardless of whether gup-fast is supported or
not.

It does not, GUP users do not interact with addres_space or mmu
notifiers

Ok, but the SIGKILL from the memory_failure() will drop the pin?

Can memory_failure() find the right processes to kill if the memory
registration has been passed by SCM_RIGHTS?