FW: [openib-general] Minutes from DAPL BOF at OpenIB Workshop

[Yaron Haviv]

Just to add there is a Lustre NAL over kDAPL in development
And few other application specific protocols done over kDAPL I know of
All those protocols Arkady mentioned can work on both RDMA technologies
and where designed in such a way (I'm familiar with their code and
architecture).

And another grate benefit of kDAPL is the simplification of the Verbs &
Access Layer API, making the ULP's simpler to implement, where a lot of
common functionality is done by a shared library (kDAPL) 
And with a socket like connection establishment flow, etc'

If we want IB to be successful we need to find a way for software
developers to easily build implementations over it (even if not all of
the Applications are open and part of the Linux tree), forcing all Linux
RDMA developers to code to Verbs, CM, SA, ... is probably not the best
approach (the IB spec is many pages as you all know).

For all the guys worried about performance degradation, the latest Verbs
vs DAPL benchmark we did we got 100% the same BW and ONLY 200ns latency
difference.

There is agreement that the current kDAPL API and implementation are not
Linux friendly, and as mentioned before a bunch or people volunteered at
Sonoma to do the work involved in changing it, and agree to make kDAPL
API different than uDAPL and more suitable for kernel.

Yaron

> -----Original Message-----
> From: openib-general-bounces at openib.org [mailto:openib-general-
> bounces at openib.org] On Behalf Of Kanevsky, Arkady
> Sent: Friday, February 11, 2005 1:49 AM
> To: Libor Michalek; Matt Leininger
> Cc: Christoph Hellwig; openib-general at openib.org; Tom Duffy
> Subject: RE: FW: [openib-general] Minutes from DAPL BOF at OpenIB
Workshop
> 
> For kDAPL:
> The iSER has been submitted to Open Ib by Voltaire already.
> NFS-RDMA is at http://sourceforge.net/projects/nfs-rdma/.
> 
> For uDAPL: Oracle, DB2 and MPI.
> I am not aware if there is an open source MPI version on uDAPL.
> 
> These are publicly known.
> 
> As far as changing the uDAPL or kDAPL APIs.
> There are application already writen to them.
> There are implementation of these APIs on other platforms besides
Linux.
> It is in nobody's interest to splinter the user community.
> We need the same API on all platforms.
> If there is a good technical reason to change some specific APIs we
> should consider it.
> But the "burn the spec" approach is not a rationale one.
> If we need to change implementation or some definitions in header
files
> it is feasible.
> 
> As far as other transport. As people already mentioned iWARP (IETF
> RDDP).
> IBM talked at the BOF about RNIC PI which is being developed as a
level
> of
> abstraction on the lower end to "discover" all the need info about
> RNIC/HCA.
> It is still no ready so we will start with gen2.
> But lets not loose site of what DAPL brings:
> OS independent,
> Transport independent,
> RDMA APIs!!!
> 
> Thanks for jumping on the code so quickly.
> Arkady
> Chair of DAT Collaborative
> 
> Arkady Kanevsky                       email: arkady at netapp.com
> Network Appliance                     phone: 781-768-5395
> 375 Totten Pond Rd.                  Fax: 781-895-1195
> Waltham, MA 02451-2010          central phone: 781-768-5300
> 
> 
> 
> > -----Original Message-----
> > From: Libor Michalek [mailto:libor at topspin.com]
> > Sent: Thursday, February 10, 2005 4:03 PM
> > To: Matt Leininger
> > Cc: Christoph Hellwig; openib-general at openib.org; Tom Duffy
> > Subject: Re: FW: [openib-general] Minutes from DAPL BOF at
> > OpenIB Workshop
> >
> >
> > On Thu, Feb 10, 2005 at 12:36:39PM -0800, Matt Leininger wrote:
> > > On Thu, 2005-02-10 at 12:27 -0800, Grant Grundler wrote:
> > > > On Thu, Feb 10, 2005 at 12:05:58PM -0800, Matt Leininger wrote:
> > > > >   uDAPL - Oracle, MPI
> > > > >   kDAPL - iSER, NFS over RDMA, Lustre?
> > > >
> > > > Lustre will use Sandia Portals AFAIK.
> > > > Anyone know what Portals will use?
> > > > They might directly program to VAPI or something.
> > > >
> > >   There will be a Portals over verbs.  At some point there may be
a
> > > Portals over kDAPL to support both RDMA ethernet and IB.
> >
> >   Yup, that's one of the bigger questions, can it abstract
> > away the differences between two different RDMA technologies?
> > Having a RDMA ethernet and IB providers for kDAPL is
> > insufficient, one would need to show an actual, non-trivial,
> > protocol that works ontop of either provider with no, or
> > little, modification/ifdef'ing.
> >
> > -Libor
> >
> >
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