Re: [PATCH 6/6] drivers/IB,core: reduce scope of mmap_sem

[Christopher Lameter]

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@xxxxxxxxx>