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

[Michael S. Tsirkin]

Quoting r. Roland Dreier <roland at topspin.com>:
> Subject: Re: ip over ib tx/rx split
> 
>     Michael> Hi!  The following simple patch splits the tx and rx
>     Michael> completions for ip over ib to separate cqs.  This shall
>     Michael> get better performance on SMP due to reduced cq lock
>     Michael> contention.
> 
> I tried something similar and even split ipoib_ib_completion() into
> two functions (to save dispatching between RX and TX completions).  I
> was not able to measure any performance improvement.

This wa slikely before we removed the qptable lock in cq poll?

> In fact I'm not convinced that this should be better, since it may
> cause more interrupts and reduce the natural interrupt coalescing
> effect that having all completions go to the same queue has.

It cant , interrupt coalescing is done by eq, not by cq.

>  - Roland
> 

-- 
MST - Michael S. Tsirkin