LMbench shows some differences several local
communication, local bandwidth, and context switch
metrics between 2.4.19-pre10-ac2 and 2.4.19-pre10-mjc1.
The latency/bandwidth differences are similar to
2.4.19-pre10aa2 and 2.4.19-jam2, but bigger.
In trying to isolate the differences in the aa/jam
series, it appeared the irqrate/irqbalance in jam2
was the differentiating factor.
mjc1 and ac2 are similar to jam/aa. mjc1 is a patchset
to ac2. mjc1 doesn't include irqrate/irqbalance though.
I ran ac2 with 1 cpu enabled on a quad xeon to get a
better idea of how processor affinity affects lmbench.
Analysis of mjc1, ac2, and ac2 with 1 cpu is here:
http://home.earthlink.net/~rwhron/kernel/lmbench_affinity.html
comments, suggestions welcome.
--
Randy Hron
http://home.earthlink.net/~rwhron/kernel/bigbox.html