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Date:   Mon, 21 Jan 2019 21:53:24 +0000
From:   Christopher Lameter <cl@linux.com>
To:     Davidlohr Bueso <dave@stgolabs.net>
cc:     akpm@linux-foundation.org, dledford@redhat.com, jgg@mellanox.com,
        jack@suse.de, ira.weiny@intel.com, linux-rdma@vger.kernel.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH 6/6] drivers/IB,core: reduce scope of mmap_sem
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On Mon, 21 Jan 2019, Davidlohr Bueso wrote:

> ib_umem_get() uses gup_longterm() and relies on the lock to
> stabilze the vma_list, so we cannot really get rid of mmap_sem
> altogether, but now that the counter is atomic, we can get of
> some complexity that mmap_sem brings with only pinned_vm.

Reviewd-by: Christoph Lameter <cl@linux.com>