[openib-general] [PATCH/RFC] IB/ipoib: add selective tx signaling - performance measurements

[Michael S. Tsirkin]

> Tests with iperf and netperf for unicast and multicast destinations show
> an improvement in the ability of user applications to xmit packets. 
> 
> Examples: Number of successful writes as reported by 30 seconds UDP_STREAM of 100 byte packets.
> Tested with netperf on Dual CPU (64bit Intel Xeon 3GHz) running linux-2.6.20-rc1 (sender) and
> OFED-1.1 (receiver)

IMO netperf reporting is actually not too informative without stats settings.
Try running with e.g. -i 10,2 -I 99,5 - you might discover that your numbers are
only accurate within 30%

> Note that the results below show improvement only for TX so we see an end to end packet loss.

Hmm, as long as packet drops increase, BW improvements in UDP don't sound
too convincing, do they? You can get infinite BW at 100% drop ...

> Improving the receiver (NAPI) will reduce the packet loss. 

Needs testing with NAPI patch then?

-- 
MST