Re: [mildly OT] Some info about Python

[Stefan <ste@...>]

Am 15.01.2020 um 23:35 schrieb Andre Leiradella:
> On 15/01/20 22:17, Stefan wrote:
> > Well, that's exactly the problem with area allocators: What if your
> > data no longer fits into your area?
> You can create huge linear allocators. Bonus: if a bogus script exhausts 
> the allocator, the script will end.
> > Abusing virtual memory is extremely hacky.
>
> Not at all.
>
> Cheers,
>
> Andre

Well, it certainly is an interesting idea. But it has many drawbacks:
 * It only works for one state at a time (if I get your approach right)
 * There will be a lot of dead memory (Lua uses realloc shrinking often)
 * It assumes you have enough virtual memory (only x64)
 * vm.overcommit_memory or equivalent must be enabled
 * Users will complain about what top/Taks manager shows them
 * Memory use has an hard upper limit now; or you need to check it for 
every allocation

Also, the current glibc allocator is *damn* fast. I tried to outsmart it
for a very narrow use case[1] and glibc malloc was still not that much 
slower - while being a general allocator and threadsafe.

But thanks for the input anyways :)

Greetings

[1] https://github.com/evelance/slaballoc64