[openib-general] [PATCH] 2/2 : ip over ib tx/rx split

[Michael S. Tsirkin]

Quoting r. Roland Dreier <roland at topspin.com>:
> Subject: Re: [openib-general] [PATCH] 2/2 : ip over ib tx/rx split
> 
>     Roland> The only difference is that we unlock the receive CQ and
>     Roland> lock the send CQ in the middle.
> 
>     Michael> Are you sure?  I *do* have msi-x on these machines.
> 
> Of course I'm not sure, but as far as I know, with the current drivers
> even with MSI-X there's still only one completion interrupt handler,
> which can only run on one CPU at a time.
> 
> Of course allowing different CQs to be bound to different interrupt
> handlers by creating multiple completion EQs is an good extension that
> I plan on implementing, but it's not written yet.  Even when it's done
> I'm not sure that having IPoIB run multiple interrupt handlers at once
> is worth it.  It's fun to get huge numbers out of IPoIB but presumably
> people want some CPU left over to do real work.
> 
>  - R.
> 

Sounds convincing. So the improvement is probably due to
better send/receive parallelism we are getting in mthca.


-- 
MST - Michael S. Tsirkin