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

From: Dan Williams
Date: Mon Mar 29 2021 - 19:25:30 EST


On Thu, Mar 25, 2021 at 7:34 AM Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>
> On Thu, Mar 18, 2021 at 10:03:06AM -0700, Dan Williams wrote:
> > 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?