[openib-general] SDP perf drop with 2.6.15

[Grant Grundler]

Michael,
The last couple of SDP_RR perf data are alarming low.
Worse than 10GigE on the same HW.


$ fgrep "1       1      60.0" openib-perf-200*/rx260*/sdprr-tx1.out
openib-perf-2005/rx2600-r3984/sdprr-tx1.out:16384  87380  1       1      60.00   18483.92  7.14   6.93   7.721   7.503 
openib-perf-2005/rx2600-r4371/sdprr-tx1.out:16384  87380  1       1      60.01   18466.79  4.70   4.63   5.088   5.010 
openib-perf-2006/rx2600-r4371/sdprr-tx1.out:16384  87380  1       1      60.01   18466.79  4.70   4.63   5.088   5.010 
openib-perf-2006/rx2600-r4800/sdprr-tx1.out:16384  87380  1       1      60.00   13898.76  53.74  7.58   77.327  10.904
openib-perf-2006/rx2600-r4929/sdprr-tx1.out:16384  87380  1       1      60.00   13902.33  6.29   8.84   9.043   12.718

r4800 was the first time I'd used 2.6.15.
I believe the other numbers are 2.6.14.

CPU utilization numbers are just alot higher.
Makes me think it's a change in the interrupt code path.
Any clues on where I might start with this?

thanks,
grant