[Qgis-psc] Performance regressions (was QGIS 2.18 bug fixing effort)

[Matthias Kuhn]

On 5/24/17 2:19 PM, Paolo Cavallini wrote:

> Il 24/05/2017 14:17, Matthias Kuhn ha scritto:
>
>> There are a couple of different ways to measure performance (wall clock,
>> cpu time) and a couple of external constraints (foremost I/O based) that
>> have a strong effect on performance measurements.
> AFAICR Radim did something like this several years ago. Not sure whether
> this is still usable today.
> I agree it could be a good addition to the automatic test suite.
> All the best.
I think this is still usable (qgis_bench IIRC).

What it does: give usable measurements when executed on the same
environment for different projects, different QGIS versions, different
build parameters, different databases...

What it not does: produce values that are comparable when executed on a
non-stable system like travis CI. Performance on this system varies from
day to day and we are never sure if a code change or some other change
on the system (hardware, software, operating system...) is responsible
for some measured "performance regression".

Matthias