Re: 2nd round of xen benchmarking

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Aug 21, 2024 at 06:09:46PM -0000, Michael van Elst wrote:
> I've tested just the 'make' (no 'make clean') and SSD instead
> of tmpfs) on a i5-2520M (dual core + HT) running 10.99.11.
> 
> As a comparison, some openssl speed benchmarks for something that should
> be less affected by hypervisor calls and MMU tables.
> 
> 
> DomU (one vpcu, cpus="2", i.e. binding to the second physical core):
> 
> 82.564u 120.134s 3:29.73 96.6%  857+416k 0+20101io 43pf+0w
> 83.227u 119.156s 3:30.40 96.1%  858+411k 74+20126io 1774pf+0w
> 
> AES-128-CBC 70863.43k  80367.31k  83191.41k  84202.06k  84429.31k  84494.63k
> ChaCha20   206227.66k 388520.22k 824340.16k 893265.14k 912746.02k 912681.33k
> 
> 
> against Dom0 (dom0_max_vcpus=1, no guest)
> 
> 60.420u 107.238s 2:54.59 96.0%  1036+500k 122+1393io 1835pf+0w
> 61.254u 107.165s 2:55.10 96.1%  1032+498k 119+1378io 1835pf+0w
> 
> AES-128-CBC 68896.51k  79475.74k  82082.92k  83084.77k  83316.83k  83319.50k
> ChaCha20   203695.15k 384909.19k 813382.84k 881179.87k 901193.83k 901486.15k
> 
> 
> against Bare metal: (all CPUs, or just just cpu#0 online, no difference):
> 
> 44.286u 21.338s 1:08.30 96.0%   2649+1105k 112+1327io 1922pf+0w
> 44.048u 20.948s 1:10.61 92.0%   2674+1268k 117+928io 1836pf+0w
> 
> AES-128-CBC 82885.72k  95674.52k  99363.95k  100529.43k  100911.79k  100886.35k
> ChaCha20   247237.43k 466793.66k 989934.51k 1066972.84k 1091012.80k 1093120.17k
> 
> 
> Disabling CPU turbo mode by setting machdep.cpu.frequency.target=2500
> (instead of 2501) gets openssl numbers close to the Dom0 case, but
> still a huge difference for the m4 build.

I'm not sure why the openssl test would be different between dom0 and domU.
But I know that people here always disable turbo, and also sometimes
hyperthreading, when doing timing benchmarks. Otherwise it's almost
impossible to get reproductible results.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--