On Mon, Nov 19, 2018 at 05:56:54PM -0500, Chuck Lever wrote: > > > > On Nov 19, 2018, at 5:41 PM, Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > > > On Mon, Nov 19, 2018 at 08:16:37AM -0800, Bart Van Assche wrote: > >> On Mon, 2018-11-19 at 10:45 -0500, Chuck Lever wrote: > >>> FMR is not supported on most recent RDMA devices. It is also slower > >>> and less secure than FRWR. As discussed during the RDMA BoF at LPC > >>> 2018, it is time to remove support for FMR in the NFS/RDMA client > >>> stack. NFS/RDMA server-side uses either local memory registration or > >>> FRWR. There is no change required there to deprecate FMR. > >>> > >>> There are a few Infiniband/RoCE devices in the kernel tree that do > >>> not support MEM_MGT_EXTENSIONS, and therefore will no longer support > >>> client-side NFS/RDMA. These are: > >>> > >>> - mthca > >>> - qib > > > > Ooh, qib was not in the list when we talked on this in plumbers. That > > does change things. > > > > Dennis: Could qib be changed? HFI1 supports FRWR right? > > > >>> - usnic > >>> - hns (RoCE) > >> > >> Can someone from Intel comment on how many of their customers rely on the qib > >> driver? > >> > >> Can someone from Cisco comment on how many of their customers rely on the usnic > >> driver? > > > > Ignore usnic, it is not a RDMA driver > > > >> Can someone from Huawei comment on how many of their customers rely on the hns > >> driver? > > > > Nor was this, this is an actively used driver.. > > > > Could hns do FRWR? It is very disappointing that such a new driver > > does not support FRWR. > > > > I guess it is worth stating again that FMR is deprecated. People are > > going to be disappointed if they try to submit new drivers that don't > > support FRWR :( > > My methodology was to search for whether each driver asserts > IB_DEVICE_MEM_MGT_EXTENSIONS in device_cap_flags. Drivers might be broken here, or we might need more flags. Searching for FWMR shows hits in hns, which is encouraging... Jason
