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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Mon, 29 Mar 2021 16:24:19 -0700
Message-ID: <CAPcyv4hHHFD4cvdRmajWgYbXU5-o-jF-o6D5ud-rg4dWNqt5Ag@mail.gmail.com>
Subject: Re: [PATCH 3/3] mm/devmap: Remove pgmap accounting in the
 get_user_pages_fast() path
To:     Jason Gunthorpe <jgg@ziepe.ca>
Cc:     Joao Martins <joao.m.martins@oracle.com>,
        Christoph Hellwig <hch@lst.de>,
        Shiyang Ruan <ruansy.fnst@fujitsu.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Andrew Morton <akpm@linux-foundation.org>,
        david <david@fromorbit.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux MM <linux-mm@kvack.org>,
        linux-nvdimm <linux-nvdimm@lists.01.org>
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On Thu, Mar 25, 2021 at 7:34 AM Jason Gunthorpe <jgg@ziepe.ca> 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?