Jerome Glisse <[email protected]> writes: > On Tue, Oct 25, 2016 at 09:56:35AM +0530, Aneesh Kumar K.V wrote: >> Jerome Glisse <[email protected]> writes: >> >> > On Mon, Oct 24, 2016 at 10:01:49AM +0530, Anshuman Khandual wrote: >> > >> I looked at the hmm-v13 w.r.t migration and I guess some form of device >> callback/acceleration during migration is something we should definitely >> have. I still haven't figured out how non addressable and coherent device >> memory can fit together there. I was waiting for the page cache >> migration support to be pushed to the repository before I start looking >> at this closely. >> > > The page cache migration does not touch the migrate code path. My issue with > page cache is writeback. The only difference with existing migrate code is > refcount check for ZONE_DEVICE page. Everything else is the same.
What about the radix tree ? does file system migrate_page callback handle replacing normal page with ZONE_DEVICE page/exceptional entries ? > > For writeback i need to use a bounce page so basicly i am trying to hook > myself > along the ISA bounce infrastructure for bio and i think it is the easiest path > to solve this in my case. > > In your case where block device can also access the device memory you don't > even need to use bounce page for writeback. > -aneesh
