Stephan Diestelhorst
2005-Jul-14 12:01 UTC
[Xen-devel] [PATCH]Improve ttcp performance for domUs
Recent tests on the default setup of domains in sedf showed a dramatic
slowdown in network performance (namely ttcp). I did some benchmarks,
results:
(machine is a dual Xeon, but I used noht and nosmp to emulate uniproc.
performance, network is 1Gb/s)
domU->external
external: ttcp -r -s -fm -l 131072
domU: ttcp external -t -s -fm -l 131072 -n 8192
bvt (default): 385.07 Mbit/s!
sedf (default, i.e. dom0: 15/20, domU: weight 1): 294.15 Mbit/sec
sedf(dom0: 5/20, domU: weight 1): 366.93 Mbit/sec
sedf(dom0: 5/20, domU: 5/20) 411.72 Mbit/sec
=> Set dom0 by default to 5/20 restores most of the performance (actually
setting it even lower should increase performance further, because more
batching will occur! quick test of 3/20 revealed: 395 Mb/s, but it might
impact latency!)
Signed-off by: Stephan.Diestelhorst@{cl.cam.ac.uk, inf.tu-dresden.de}
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