On Tue, Dec 10, 2019 at 11:24:21PM -0500, Doug Ledford wrote: > On Tue, 2019-12-10 at 08:54 +0200, Leon Romanovsky wrote: > > On Mon, Dec 09, 2019 at 02:07:06PM -0500, Doug Ledford wrote: > > > > > > I've taken these two patches into for-rc (with fixups to the commit > > > message on the second, as well as adding a Fixes: tag on the > > > second). > > > > > > I stand by what I said about not needing a compatibility flag or > > > module > > > option for the user to set. However, that isn't to say that we > > > can't > > > autodetect old soft-RoCE peers. If we get a packet that fails CRC > > > and > > > has pad bytes, then re-run the CRC without the pad bytes and see if > > > it > > > matches. If it does, we could A) mark the current QP as being to an > > > old > > > soft-RoCE device (causing us to send without including the pad bytes > > > in > > > the CRC) and B) allocate a struct old_soft_roce_peer and save the > > > guid > > > into that struct and then put that struct on a list that we then > > > search > > > any time we are creating a new queue pair and if the new queue pair > > > goes > > > to a guid in the list, then we immediately flag that qp as being to > > > an > > > old soft roce device and get the right behavior. It would slow down > > > qp > > > creation somewhat due to the list search, but probably not enough to > > > worry about. No one will be doing a 1,000 node cluster MPI job over > > > soft-RoCE, so we should never notice the list length causing search > > > problems. A patch to do something like that would be welcome. > > > > Do you find this implementation needed? I see RXE as a development > > platform and in my view it is unlikely that someone will run RXE in > > production with mixture of different kernel versions, which requires > > such compatibility fallback. > > It's not a requirement, that's why I took the patches as they were. It > would just be a "nice to have". I see, thanks > > -- > Doug Ledford <dledford@xxxxxxxxxx> > GPG KeyID: B826A3330E572FDD > Fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD
