> Sometimes for testing we turn it off in order to identify identity test
bugs.

Interesting! Well, if the option is useful for testing, that's certainly a
good reason to keep it.

> Also, eveonline was controlling this to save memory.

Also interesting. I feel like there must be something about their setup
that I'm not imagining, because this is a pretty tiny amount of memory (9
kB) on the scale of a typical Python server process in my experience.

Or do you mean they were increasing the numbers? One thought I had looking
at this was actually that it would be interesting to do some measurements
and try to pick new (default) values for these parameters - it looks like
they're the same today as in 1993, and it's likely that with all that's
changed in typical hardware since then (plus the switch from Python ints +
longs to only what we used to call longs), the optimum values today are
different from the optimum in 1993. And certainly one of the effects of
this optimization when its hit rate is good is reducing memory consumption
- you have only one 17 instead of however many you make.

I'll rework the explicit-return patch to send without this change. It'll be
a little trickier but should be entirely doable.

On Sat, Aug 10, 2019, 23:19 Raymond Hettinger <report@bugs.python.org>
wrote:

>
> Raymond Hettinger <raymond.hettinger@gmail.com> added the comment:
>
> P.S.  Making the returns explicit is a reasonable change to make, but the
> core #ifdef logic should remain.
>
> ----------
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue37812>
> _______________________________________
>