[openib-general] Re: SDP perf drop with 2.6.15

[Michael S. Tsirkin]

Quoting r. Grant Grundler <iod00d at hp.com>:
> Subject: SDP perf drop with 2.6.15
> 
> 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

oprofile should show where we are spending the time.

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MST