[ofw] [RFC] [PATCH 1/2] work_queue: new abstraction for queuing work

[Sean Hefty]

>I know you can with the IRP, I don't know though if the WDF framework reserves
>those fields (Tail.Overlay.DriverContext array).

I tried it and it works.  I'll submit a new patch shortly that uses the work
items directly.

I also modified the work queue to only process one queued request and requeue
the work item if more work remains, but the winverbs code doesn't call it at the
moment.

>Complib already has what you need: Quick pool.

I don't know that it's desirable to allocate 1 work item per connection.  The
HCA likely has a limited number of requests that it can service.  Queuing, say,
3000 modify QP calls at once after a large MPI run can be worse on overall
performance.  That many work items essentially blocks all system threads
relative to how quickly a single HCA can service the modify requests.  This was
why I used a fix work item pool per WV provider.

- Sean