[RFC][v4][PATCH 0/7] clone_with_pids() system call

[Serge E. Hallyn]

Quoting Eric W. Biederman (ebiederm at xmission.com):
> Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com> writes:
> 
> > === NEW CLONE() SYSTEM CALL:
> >
> > To support application checkpoint/restart, a task must have the same pid it
> > had when it was checkpointed.  When containers are nested, the tasks within
> > the containers exist in multiple pid namespaces and hence have multiple pids
> > to specify during restart.
> >
> > This patchset implements a new system call, clone_with_pids() that lets a
> > process specify the pids of the child process.
> >
> > Patches 1 through 5 are helpers and we believe they are needed for application
> > restart, regardless of the kernel implementation of application restart.
> 
> I'm not very impressed.
> 
> - static int alloc_pidmap(struct pid_namespace *pid_ns)
> + static int alloc_pidmap(struct pid_namespace *pid_ns, int pid_max, int last_pid)

Regardless of Suka's patch, note that I did send you a patch back on march 21
to make pid_max a pidns property.  I suspect that's still something we
want. 

-serge