Re: [PATCH v4 0/1] Use HMM for ODP v4

From: Christoph Hellwig
Date: Fri May 24 2019 - 02:43:55 EST

On Thu, May 23, 2019 at 04:10:38PM -0300, Jason Gunthorpe wrote:
> On Thu, May 23, 2019 at 02:24:58PM -0400, Jerome Glisse wrote:
> > I can not take mmap_sem in range_register, the READ_ONCE is fine and
> > they are no race as we do take a reference on the hmm struct thus
> Of course there are use after free races with a READ_ONCE scheme, I
> shouldn't have to explain this.
> If you cannot take the read mmap sem (why not?), then please use my
> version and push the update to the driver through -mm..

I think it would really help if we queue up these changes in a git tree
that can be pulled into the driver trees. Given that you've been
doing so much work to actually make it usable I'd nominate rdma for the
"lead" tree.