The APIs are going to change quite dramatically in the near future when the
only way to run at 10Gb/s is with an offload engine. There’s a lot of work
going on in this arena, especially in the IETF, Microsoft and other major
vendors.
Microsoft’s Winsock Direct is a start, but it introduces inefficiencies by
mapping traditional Winsock over InfiniBand like RDMA semantics. For
maximum efficiency, you’d want to use SDP directly.
To use an offload engine or some of the proposed RDMA functionality to
greatest efficiency requires the ability to pre-post large numbers of
buffers and have asynchronous notification. Winsock with it’s overlapped
I/O and asynchronous completion methods is probably quite adaptable to the
required semantics. But the old BSD sockets is hopeless for it. Linux and
Unixen are going to have their work cut out to make some very major changes
in the networking stacks in the very near future.
That’s not to say that you couldn’t continue to use a BSD sockets mapping
over an offload engine, just that it wouldn’t be very efficient or would
require a card with more memory than the vendors are looking to use (i.e.
more expensive). Many vendors in this space are looking to produce cards
with effectively zero memory and do direct data placement into the
pre-posted buffers. In this scenario the BSD sockets APIs being unable to
pre-post buffers would have an interesting effect on the TCP window and
other things.
Mark.
At 15:37 04/12/2002 -0800, Bi Chen wrote:
BSD socket is inefficient to be used on server that must handle large about
of concurrent TCP connections or UDP requests on Windows Platform because
it lacks of nonblocking or overlapped caps. One can use select to relief the
problem somewhat, but not much. In any cases, there will be heck lot of
thread context switching and using a lot of threads. Using Overlapped
WinSocket along with IO completion port and/or OS (Windows) provided thread
pool, saves all those boatload of overhead.On Linux, it is a bit different story. However, Liunx community, especially
Oralce realize that blocking BSD socket and lack of asynchronies IO is hugh
drag in their quest to beat server performance of Windows. They are adding
those in 2.5 kerenl.Bi
-----Original Message-----
From: Maxim S. Shatskih
[mailto:xxxxxmailto:xxxxx@storagecraft.com]
>Sent: Wednesday, December 04, 2002 2:53 PM
>To: NT Developers Interest List
>Subject: [ntdev] RE: TDI client driver Vs. user mode sockets applicati
>on
>
>RE: [ntdev] RE: TDI client driver Vs. user mode sockets applicationIn what
>respect namely the BSD socket model is inefficient?
>
> Max
></mailto:xxxxx>