Re: [RFC] Add option to mount only a pids subset

[Andy Lutomirski]

On Mon, Mar 6, 2017 at 3:05 PM, Alexey Gladkov <gladkov.alexey@xxxxxxxxx> wrote:
>
> After discussion with Oleg Nesterov I reimplement my patch as an additional
> option for /proc. This option affects the mountpoint. It means that in one
> pid namespace it possible to have both the whole traditional /proc and
> /proc with only pids subset.
>

I like this.  I think you should split it into two patches, though:
one that reworks how procfs gets mounted and one that makes adds the
new functionality.

Djajal had some concerns about the first part breaking applications
that use stat and expect certain behavior.  This should be manageable,
though, but making stat work appropriately.