Messages in this thread | | | Date | Tue, 21 Nov 2017 15:05:01 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH v2 1/4] mm: introduce get_user_pages_longterm |
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On Tue, 14 Nov 2017 11:56:34 -0800 Dan Williams <dan.j.williams@intel.com> wrote:
> Until there is a solution to the dma-to-dax vs truncate problem it is > not safe to allow long standing memory registrations against > filesytem-dax vmas. Device-dax vmas do not have this problem and are > explicitly allowed. > > This is temporary until a "memory registration with layout-lease" > mechanism can be implemented for the affected sub-systems (RDMA and > V4L2).
Sounds like that will be unpleasant. Do we really need it to be that complex? Can we get away with simply failing the get_user_pages() request? Or are there significant usecases for RDMA and V4L to play with DAX memory?
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