Re: [PATCH] pidns: reboot_pid_ns: use SEND_SIG_FORCED instead of force_sig()

[Serge Hallyn <serge.hallyn@canonical.com>]

Quoting Oleg Nesterov (oleg@redhat.com):
> Hi Serge,
> 
> On 04/13, Serge Hallyn wrote:
> >
> > Quoting Oleg Nesterov (oleg@redhat.com):
> > > cf3f8921 "pidns: add reboot_pid_ns() to handle the reboot syscall"
> > > uses force_sig() to kill the SIGNAL_UNKILLABLE cinit, this was the
> > > only choice.
> > >
> > > After 629d362b we can use SEND_SIG_FORCED instead, force_sig() has
> > > the special semantics and should be avoided if possible.
> > >
> > > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> >
> > Hi Oleg,
> >
> > I like the patch in theory, however after applying it containers are
> > no longer able to shutdown/reboot.  I can externally kill them with
> > lxc-stop, but internal shutdown fails.
> 
> Oh, thanks a lot for testing.
> 
> Strange... I even tested this change, but only in the root namespace.
> OK, thanks, I'll investigate. I hope you verified your kernel has
> 629d362b commit ;)

You know, I did.  But in the wrong tree!

Sorry.  Will add that patch, re-build and re-test.

-serge