Re: [PATCH RFC V11 15/18] kvm : Paravirtual ticketlocks support forlinux guests running on KVM hypervisor

From: Ingo Molnar
Date: Fri Aug 02 2013 - 05:23:39 EST



* Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx> wrote:

> On 08/01/2013 02:34 PM, Raghavendra K T wrote:
> >On 08/01/2013 01:15 PM, Gleb Natapov wrote:
> >>>Shall I consider this as an ack for kvm part?
> >>>
> >>For everything except 18/18. For that I still want to see numbers. But
> >>18/18 is pretty independent from the reset of the series so it should
> >>not stop the reset from going in.
> >
> >Yes. agreed.
> >I am going to evaluate patch 18 separately and come with results for
> >that. Now we can consider only 1-17 patches.
> >
>
> Gleb,
>
> 32 core machine with HT off 32 vcpu guests.
> base = 3.11-rc + patch 1 -17 pvspinlock_v11
> patched = base + patch 18
>
> +-----------+-----------+-----------+------------+-----------+
> dbench (Throughput in MB/sec higher is better)
> +-----------+-----------+-----------+------------+-----------+
> base stdev patched stdev %improvement
> +-----------+-----------+-----------+------------+-----------+
> 1x 14584.3800 146.9074 14705.1000 163.1060 0.82773
> 2x 1713.7300 32.8750 1717.3200 45.5979 0.20948
> 3x 967.8212 42.0257 971.8855 18.8532 0.41994
> 4x 685.2764 25.7150 694.5881 8.3907 1.35882
> +-----------+-----------+-----------+------------+-----------+

Please list stddev in percentage as well ...

a blind stab gave me these figures:

> base stdev patched stdev %improvement
> 3x 967.8212 4.3% 971.8855 1.8% 0.4

That makes the improvement an order of magnitude smaller than the noise of
the measurement ... i.e. totally inconclusive.

Also please cut the excessive decimal points: with 2-4% noise what point
is there in 5 decimal point results??

Thanks,

Ingo
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