[openib-general] Sockets Extensions Completed

[Libor Michalek]

On Fri, Jan 07, 2005 at 11:03:47AM -0800, Josh England wrote:
> This is probably not the right forum, but how would you say the ES-API
> compares with DAPL?

  ES-API appears to be much closer to the Linux AIO extensions then to
DAPL. DAPL provides an explicit RDMA API for applications while AIO and
ES-API allow for asynchronous operations on normal sockets, so you can
perform standard socket operations, plus asynchronous operations. AIO 
and ES-API still maintain streaming socket symantics, while DAPL provides
full RDMA capabilities, such as explicit memory placement.

  ES-API goes a few steps further then the existing Linux AIO in providing
explicit memory registration, which may or may not be a significant win,
depending on application. Using Linux AIO, which does not have explicit 
memory registration, my existing SDP implementation can reach full data
rate. The registration is done on the fly using FMRs

-Libor


> On Fri, 2005-01-07 at 07:12 -0800, Michael Krause wrote:
> > At 03:57 PM 1/6/2005, Josh England wrote:
> > > Is it the API that is completed, or is there an implementation
> > > written already?
> > 
> > The API specification has been completed so now people can implement
> > if there is interest.  The API is part of the Unix branding effort
> > done within the OpenGroup and is available to all for free.  Given the
> > desire to implement open standards within the open source community,
> > this would seem like a logical API to support on Linux.  How this is
> > actually started / implemented on Linux is an open question.  My main
> > reason for providing the spec notification availability here is that
> > the socket extensions when combined with SDP will provide optimum
> > performance when used in conjunction with RDMA interconnects while
> > providing a fairly familiar interface to most network application
> > writers.  For those that have implemented MPI over Sockets (not all
> > have done this), this would also provide a cleaner mapping and still
> > allow transparent access to RDMA with minimum performance impact.  
> > 
> > Mike
> > 
> > 
> > > -JE
> > > 
> > > On Thu, 2005-01-06 at 10:31 -0800, Michael Krause wrote:
> > > >         
> > > > FYI.....The specification can be found at: 
> > > > 
> > > > http://www.opengroup.org/bookstore/catalog/c050.htm
> > > > 
> > > > Use of this new interface will enable Sockets based applications
> > > to
> > > > fully exploit the performance of RDMA interconnects through the
> > > SDP
> > > > wire protocol.   This API also provides explicit memory management
> > > > taking some of the guesswork out of this thorny problem which can
> > > > result in some performance loss and implementation complexity
> > > within
> > > > the SDP layer.
> > > > 
> > > > Mike 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > Extended Sockets API (ES-API), Issue 1.0
> > > > The Extended Sockets API (ES-API) Technical Standard provides
> > > > extensions to the traditional socket API to support improved
> > > > efficiency in network programming. The ES-API includes:
> > > synchronous IO
> > > > and control operations on sockets; event queue-based management of
> > > > asynchronous operations; and pre-registering of memory regions
> > > that
> > > > will be the subject of IO operations. These facilities are
> > > intended to
> > > > support: improved efficiency when dealing with high numbers of
> > > socket
> > > > file descriptors; 'zero-copy' transmit and receive operations; and
> > > > improved buffer management. The ES-API also includes routines that
> > > > provide asynchronous IO and control operations, asynchronous
> > > operation
> > > > management, and memory registration functions for applications
> > > > manipulating sockets.
> > > > 
> > > > 
> > > > 
> > > > Bibliographic Details
> > > > Consortium Specifications 
> > > > 
> > > > Catalog number C050 
> > > > ISBN 1931624526 
> > > > Jan 2005
> > > > 
> > > > OO. 72 pages. 
> > > > 
> > > > _______________________________________________
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> > > > http://openib.org/mailman/listinfo/openib-general
> > > > 
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> 
> 
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