[Python-Dev] The untuned tunable parameter ARENA_SIZE

[Antoine Pitrou]

On Fri, 2 Jun 2017 13:23:05 -0500
Tim Peters <tim.peters at gmail.com> wrote:
> 
> While I would like to increase the pool size, it's fraught with
> danger.

What would be the point of increasing the pool size?  Apart from being
able to allocate 4KB objects out of it, I mean.

Since 4KB+ objects are relatively uncommon (I mean we don't allocate
hundreds of thousands of them per second), I don't think it's really
worthwhile trying to have the small object allocator handle them.

> It would be nice to find a different way for pymalloc to figure out
> which addresses belong to it.  The excruciating Py_ADDRESS_IN_RANGE
> manages to do it in small constant (independent of the number of
> arenas and pools in use) time, which is its only virtue ;-)

So, to sum it up, it's excruciating but fast and works reliably.  Why
change it?

Regards

Antoine.