story: add max memory cap to pyston

[dPeS]

I cannot tell CPython that memory is limited to value X. I run thousands of python workers @mesos stack where I need to pre slice the memory. That is big operation issue with python.

It will be killer feature to have something similar to "xmx" parameter in java world. I know that pyston won't free needed memory but it should be aware of max memory and make more pressure on GC work.

[kmod]

That's a really interesting idea! What would happen if you approach the memory limit? I would imagine that there is usually relatively little memory for the cycle collector to free since most memory management is done via refcounting, but maybe there are other space-time tradeoffs that could be adjusted.

[dPeS]

What would happen if you approach the memory limit?

in java world GC is fired much more often + doing more careful work

In general python world has a lot of memory quirks (such [1]) - for my OPS point of view: runtime that is aware of memory limits would be large step forward. Right now we loose http requests while CPython is killed by mem limit on cgroup and I have no way to tell if it was: memory leak or legit memory allocation since "maybe GC was about to fire but didn't manage to" (because of oom kill).

[1] pandas-dev/pandas#2659 (comment)