[cairo] Cairo performance testing with X11 forwarding

[Chris Wilson]

On Mon, 11 Jun 2012 18:46:13 -0400, Patrick Wilbur <patrick.wilbur at gmail.com> wrote:
> Hey all,
> 
> I'm new to cairo-perf-trace. I'm trying to benchmark ssh -X forwarding
> versus a local X server using the traces in the benchmark/ directory (from
> the traces repository).
> 
> Over ssh -X, cairo-perf-trace chromium-tabs.trace seemed to work and
> terminate fine. The evolution.trace seems to hang (gave it an hour to
> complete, but it didn't finish). The firefox traces also seem to hang. I'm
> running on Ubuntu 12.04.
> 
> Any reasons you can think of that this is happening? (Also, any reasons why
> this isn't a good benchmark and, if so, what would be the best way to
> accomplish what I'm trying to test?)

For the stated purpose of looking at the overhead incurred through SSH X
forwarding, it is fine. Rendering is almost entirely one-way traffic
with very little round-trips so what you are mostly measuring is the effect
of compression upon throughput, and given enough cores shouldn't see a
large difference than rendering natively on the xserver.

That it explodes timewise is indicative of a bug on your systems,
somewhere between cairo and the remote driver.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre