[systemd-devel] [RFC PATCH] proc, pidns: Add highpid

[Andy Lutomirski]

On Nov 30, 2014 1:47 AM, "Florian Weimer" <fw at deneb.enyo.de> wrote:
>
> * Andy Lutomirski:
>
> > The initial implementation is straightforward: highpid is simply a
> > 64-bit counter. If a high-end system can fork every 3 ns (which
> > would be amazing, given that just allocating a pid requires at
> > atomic operation), it would take well over 1000 years for highpid to
> > wrap.
>
> I'm not sure if I'm reading the patch correctly, but is the counter
> namespaced?  If yes, why?

It's namespaced so that CRIU can migrate/restore a whole pid namespace.

--Andy