Re: [RFC PATCH 0/4] cgroup aware workqueues

From: Tejun Heo
Date: Fri May 27 2016 - 10:17:22 EST


On Fri, May 27, 2016 at 12:22:19PM +0300, Michael Rapoport wrote:
> I've run two guests without any CPU pinning and without any actual
> interaction with cgroups
> Here's the results (in MBits/sec):
>
> size | 64 | 256 | 1024 | 4096 | 16384
> -----+-------+---------+---------+---------+---------
> (1) | 496.8 | 1346.31 | 6058.49 | 13736.2 | 13541.4
> (2) | 493.3 | 1604.03 | 5723.68 | 10181.4 | 15572.4
> (3) | 489.7 | 1437.86 | 6251.12 | 12774.2 | 12867.9
>
>
> From what I see, for different packet sizes there's different approach
> that outperforms the others.
> Moreover, I'd expect that in case when vhost completely takes over the
> worker thread there would no be difference vs. current state.
>
> Tejun, can you help explaining these results?

Heh, the only thing I can tell is the tests seem noisy and weren't run
enough times to draw any conclusion. Even if the numbers were
consistent, I don't think anybody would be able to tell a lot from
just the results. If the results can be made stable, perf would be a
good place to start.

Thanks.

--
tejun