[ofw] RE: [ewg] RE: SC'09 BOF - Meeting notes and Final Slides

[Fab Tillier]

Hi Sean

Sean Hefty wrote on Thu, 19 Nov 2009 at 11:53:56

>> can't anyone get async modify QP today on any platform by just doing
>> the operation in another thread (or thread pool)?  It seems that the
>> operations themselves are heavy enough that thread dispatch, locking
>> etc is going to be significant overhead.
> 
> On WinOF this is basically how things are implemented anyway.  The lower
> level drivers are ports of the Linux drivers and do everything
> synchronously. The kernel uverbs equivalent just queues the modify calls
> to a kernel thread pool. It's not as efficient as it could be, since it
> ends up adding two context switches, but works.
> 
> I could try adding threads to the librdmacm, move the modify calls to
> those threads, and see if there's any difference.

You'll still need to have the kernel thread pool to support WinVerbs (at least on Windows.)

-Fab