Re: Re: [PATCH 4/6 v2] IB: address translation to map IP toIB addresses (GIDs)

[Sean Hefty <mshefty@ichips.intel.com>]

Roland Dreier wrote:
>  > +struct workqueue_struct *rdma_wq;
>  > +EXPORT_SYMBOL(rdma_wq);
> 
> Sean, I don't think I saw an answer when I asked you this before.  Why
> is ib_addr exporting a workqueue?  Is there some sort of ordering
> constraint that is forcing other modules to go through the same
> workqueue for things?
> 
> This seems like a very fragile internal thing to be exposing, and I'm
> wondering if there's a better way to handle it.

I responded in a different thread, but here's what I wrote:

"This is simply an attempt to reduce/combine work queues used by the Infiniband 
code.  This keeps the threading a little simpler in the rdma_cm, since all 
callbacks are invoked using the same work queue.  (I'm also using this with the 
local SA/multicast code, but that's not ready for merging.)"

There's no specific ordering constraint that's required.  We're just ending up 
with several Infiniband modules creating their own work queues (ib_mad, ib_cm, 
ib_addr, rdma_cm, plus a couple more in modules under development), and this is 
an attempt to reduce that.  If having separate work queues would work better, 
there shouldn't be anything that prevents this.

- Sean