Re: [PATCH RFC 0/2] add nproc cgroup subsystem

Tejun Heo
2015-02-28T16:43:53Z

Hello, Tim.

On Sat, Feb 28, 2015 at 08:38:07AM -0800, Tim Hockin wrote:
> I know there is not much concern for legacy-system problems, but it is
> worth adding this case - there are systems that limit PIDs for other
> reasons, eg broken infrastructure that assumes PIDs fit in a short int,
> hypothetically. Given such a system, PIDs become precious and limiting
> them per job is important.
>
> My main point being that there are less obvious considerations in play than
> just memory usage.

Sure, there are those cases but it'd be unwise to hinge long term
decisions on them. It's hard to even argue 16bit pid in legacy code
as a significant contributing factor at this point. At any rate, it
seems that pid is a global resource which needs to be provisioned for
reasonable isolation which is a good reason to consider controlling it
via cgroups.

Thanks.

--
tejun