[Ofa_boardplus] XWG meeting minutes 11/29

[Paul Grun]

This was also my understanding of Doug's original proposal.  The idea is to allow experimentation with 'emulated RDMA hardware', i.e. SoftRoCE, using the verbs API, over an Ethernet network.

>-----Original Message-----
>From: Jason Gunthorpe [mailto:jgg at ziepe.ca]
>Sent: Thursday, November 29, 2018 3:44 PM
>To: Doug Ledford <dledford at redhat.com>
>Cc: Hefty, Sean <sean.hefty at intel.com>; Paul Grun <grun at cray.com>;
>Woodruff, Robert J <robert.j.woodruff at intel.com>; Jim Ryan
><jimdryan at gmail.com>; ofa_boardplus at lists.openfabrics.org
>Subject: Re: [Ofa_boardplus] XWG meeting minutes 11/29
>
>At LPC Chunk and Bart were specifically interested in testing verbs based
>applications like NFS-RDMA and SRP. Not really a space that overlaps with
>libfabric..
>
>Jason
>
>On Thu, Nov 29, 2018 at 05:34:09PM -0500, Doug Ledford wrote:
>> You can use libfabric over TCP sockets, but it doesn't have the feel
>> of RDMA hardware.  What I was going for was something that a user
>> could do to emulate having the hardware.  This provides a platform for
>> exploring all of the aspects related to RDMA, including things like
>> configuration of devices, seeing how the OS reacts to the hardware, as
>> well as programming *any* of the RDMA APIs.  This is why I was most
>> interested in soft-iWARP or soft-RoCE.
>>
>> On 11/29/2018 5:20 PM, Hefty, Sean wrote:
>> > Woody wasn't referring to the verbs provider.  He was talking about using
>sockets over tcp.
>> >
>> > RDMA != VERBS   !!!!!
>> >
>> > If OFA still can't get this right, then, yes, there's no way anyone outside of the
>field is ever going to understand it.
>> >
>> > OFA has already made the investment.  It's harmless, been available for years,
>and is free.
>> >
>> >
>> >> You’re quite right Woody; I hadn’t thought of using libfabric with
>> >> the verbs provider running over Ethernet.
>> >>
>> >>
>> >>
>> >> Another approach is the ‘cluster on a laptop’ that I described.
>> >> That one uses KVM and standard enet virtual switches to create a
>> >> ‘cluster in a box’.
>> >>
>> >>
>> >>
>> >> In either case, Doug’s point was that the OFA is in a position to
>> >> make it easier for people to get exposed to RDMA in a harmless and
>> >> zero cost way.  I think that’s something in which the OFA should invest.
>> >> Fastest way I can imagine to accelerate the adoption of high
>> >> performance networks.
>> >>
>> >> -Paul
>> >>
>> >>
>> >>
>> >> From: Woodruff, Robert J [mailto:robert.j.woodruff at intel.com]
>> >> Sent: Thursday, November 29, 2018 1:59 PM
>> >> To: Paul Grun <grun at cray.com>; Jim Ryan <jimdryan at gmail.com>
>> >> Cc: ofa_boardplus at lists.openfabrics.org,
>> >> <ofa_boardplus at lists.openfabrics.org>
>> >> Subject: RE: [Ofa_boardplus] XWG meeting minutes 11/29
>> >>
>> >>
>> >>
>> >>> There’s no easy way to experiment with RDMA and learn about it,
>> >> without buying h/w.
>> >>
>> >>
>> >>
>> >> This is not exactly true. With OFI, it supports RDMA and we have a
>> >> sockets provider that people can use with any off the shelf
>> >> Ethernet NIC to experiment and learn about RDMA.
>> >>
>> >> In fact, we have a lot of development internally that uses the OFI
>> >> sockets provider for initial development and then later test and
>> >> tune it on hardware accelerated RDMA NICs.
>> >>
>> >>
>> >>
>> >> Woody
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> From: Ofa_boardplus [mailto:ofa_boardplus-
>> >> bounces at lists.openfabrics.org] On Behalf Of Paul Grun
>> >> Sent: Thursday, November 29, 2018 1:24 PM
>> >> To: Jim Ryan <jimdryan at gmail.com <mailto:jimdryan at gmail.com> >
>> >> Cc: ofa_boardplus at lists.openfabrics.org
>> >> <mailto:ofa_boardplus at lists.openfabrics.org> ,
>> >> <ofa_boardplus at lists.openfabrics.org
>> >> <mailto:ofa_boardplus at lists.openfabrics.org> >
>> >> Subject: Re: [Ofa_boardplus] XWG meeting minutes 11/29
>> >>
>> >>
>> >>
>> >> A tiny nit – the second to approve the minutes was Christoph.
>> >>
>> >>
>> >>
>> >> Another small-ish nit - People are dismayed at how hard it is to
>> >> test things RDMA-related especially by newbies, complicated by the
>> >> need to buy HW.
>> >>
>> >> I think it’s a little more than just testing.  There’s no easy way
>> >> to experiment with RDMA and learn about it, without buying h/w.
>> >>
>> >>
>> >>
>> >> Not-so-small nit - Gilad explained openRDMA doesn’t compete with
>> >> the OFA. Rather it provides help for those wanting to use RDMA.
>> >> They are not doing new development.
>> >>
>> >> Rather, Gilad asserted that OpenRDMA doesn’t compete with the OFA
>> >> because it is not doing new development. This is incorrect because
>> >> the OFA’s mission is not limited to development.  Our mission is to
>> >> accelerate the development and adoption of (e.g. RDMA).  No good
>> >> argument was offered for why OpenRDMA should not be hosted by the
>> >> OFA under the auspices of the existing OFVWG (which was originally
>> >> requested by MLNX and is currently chaired by MLNX).
>> >>
>> >>
>> >>
>> >> The OFA was originally formed specifically to foster the
>> >> development, support, and adoption of RDMA and stands ready to continue
>doing so.
>> >> Nothing about that has changed in our mission.
>> >>
>> >>
>> >>
>> >> -Paul
>> >>
>> >>
>> >>
>> >> From: Ofa_boardplus [mailto:ofa_boardplus-
>> >> bounces at lists.openfabrics.org] On Behalf Of Jim Ryan
>> >> Sent: Thursday, November 29, 2018 12:30 PM
>> >> To: ofa_boardplus at lists.openfabrics.org
>> >> <mailto:ofa_boardplus at lists.openfabrics.org> ,
>> >> <ofa_boardplus at lists.openfabrics.org
>> >> <mailto:ofa_boardplus at lists.openfabrics.org> >
>> >> Subject: [Ofa_boardplus] XWG meeting minutes 11/29
>> >>
>> >>
>> >>
>> >> A very complex meeting, I hope I got it right
>> >>
>> >>
>> >>
>> >> Jim
>> >
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