vmon: introduce -R/--reaper flag

Beginnings of PR_SET_CHILD_SUBREAPER mode, this only adds the
CLI flags.

Becoming a subreaper is only relevant to running commands via
vmon.  If the commands being executed fork/exec/daemonize or
otherwise may produce orphaned processes, they escape the
scoped hierarchical monitoring when init inherits them, so you
lose visibility into their actions once orphaned.

By becoming a subreaper, vmon can be the process inheriting those
orphans, so they may continue being monitored, as if vmon were
init, for its descendants.

0 files changed, 0 insertions, 0 deletions