> Krishna Kumar2/India/IBM wrote on 10/28/2010 10:44:14 AM:
>
> > > > > Results for UDP BW tests (unidirectional, sum across
> > > > > 3 iterations, each iteration of 45 seconds, default
> > > > > netperf, vhosts bound to cpus 0-3; no other tuning):
> > > >
> > > > Is binding vhost threads to CPUs really required?
> > > > What happens if we let the scheduler do its job?
> > >
> > > Nothing drastic, I remember BW% and SD% both improved a
> > > bit as a result of binding.
> >
> > If there's a significant improvement this would mean that
> > we need to rethink the vhost-net interaction with the scheduler.
>
> I will get a test run with and without binding and post the
> results later today.
Correction: The result with binding is is much better for
SD/CPU compared to without-binding:
_____________________________________________________
numtxqs=8,vhosts=5, Bind vs No-bind
# BW% CPU% RCPU% SD% RSD%
_____________________________________________________
1 11.25 10.77 1.89 0 -6.06
2 18.66 7.20 7.20 -14.28 -7.40
4 4.24 -1.27 1.56 -2.70 -.98
8 14.91 -3.79 5.46 -12.19 -3.76
16 12.32 -8.67 4.63 -35.97 -26.66
24 11.68 -7.83 5.10 -40.73 -32.37
32 13.09 -10.51 6.57 -51.52 -42.28
40 11.04 -4.12 11.23 -50.69 -42.81
48 8.61 -10.30 6.04 -62.38 -55.54
64 7.55 -6.05 6.41 -61.20 -56.04
80 8.74 -11.45 6.29 -72.65 -67.17
96 9.84 -6.01 9.87 -69.89 -64.78
128 5.57 -6.23 8.99 -75.03 -70.97
_____________________________________________________
BW: 10.4%, CPU/RCPU: -7.4%,7.7%, SD: -70.5%,-65.7%
Notes:
1. All my test results earlier was binding vhost
to cpus 0-3 for both org and new kernel.
2. I am not using MST's use_mq patch, only mainline
kernel. However, I reported earlier that I got
better results with that patch. The result for
MQ vs MQ+use_mm patch (from my earlier mail):
BW: 0 CPU/RCPU: -4.2,-6.1 SD/RSD: -13.1,-15.6
Thanks,
- KK
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