[Python-Dev] pymalloc killer

[David Abrahams]

----- Original Message -----
From: "Martin v. Loewis" <martin@v.loewis.de>


> "David Abrahams" <david.abrahams@rcn.com> writes:
>
> > ...isn't this part just a little too complicated? If I understand
> > correctly, arenas are 4K aligned pages.
>
> No, arenas are 256k areas which are split into 4k pools.
>
> > Given an address, when you find its pool header, you either find a
> > valid arena header that covers all 4K subsequent addresses, or some
> > alien memory. I think you just have to look for the address of the
> > pool header at the appropriate index in the vector. IOW, there
> > should be no need to look at the address you're deallocating after
> > finding its putative arena.
>
> The pool in question and the arena it belongs to may have different
> starting addresses (in 63 of 64 cases, they will be different).
>
> Of course, you could also build the table for pool addresses,
> assigning pool indices - but that would require 64 times as much
> memory.

OK, but I guess my question still holds: can't you just round down to
find a supposed arena address, look up the index, and see if that arena
is in the vector?

-Dave