[Python-Dev] Possible performance regression

[Victor Stinner]

Hi,

Le mar. 26 févr. 2019 à 05:27, Eric Snow <ericsnowcurrently at gmail.com> a écrit :
> I ran the "performance" suite (https://github.com/python/performance),
> which has 57 different benchmarks.

Ah yes, by the way: I also ran manually performance on
speed.python.org yesterday: it added a new dot at Feb 25.

> In the results, 9 were marked as
> "significantly" different between the two commits..  2 of the
> benchmarks showed a marginal slowdown and 7 showed a marginal speedup:

I'm not surprised :-) Noise on micro-benchmark is usually "ignored by
the std dev" (delta included in the std dev).

At speed.python.org, you can see that basically the performances are
stable since last summer.

I let you have a look at https://speed.python.org/timeline/

> | Benchmark               | speed.before | speed.after | Change
> | Significance          |
> +=========================+==============+=============+==============+=======================+
> | django_template         | 177 ms       | 172 ms      | 1.03x faster
> | Significant (t=3.66)  |
> +-------------------------+--------------+-------------+--------------+-----------------------+
> | html5lib                | 126 ms       | 122 ms      | 1.03x faster
> | Significant (t=3.46)  |
> +-------------------------+--------------+-------------+--------------+-----------------------+
> | json_dumps              | 17.6 ms      | 17.2 ms     | 1.02x faster
> | Significant (t=2.65)  |
> +-------------------------+--------------+-------------+--------------+-----------------------+
> | nbody                   | 157 ms       | 161 ms      | 1.03x slower
> | Significant (t=-3.85) |
(...)

Usually, I just ignore changes which are smaller than 5% ;-)

Victor
-- 
Night gathers, and now my watch begins. It shall not end until my death.