proc: Add an interface to get all the tasks that share a core

Core-scheduling allows tasks to share a core. The per-process interface
is the prctl(2) PR_SET_CORE_SCHED added in earlier patches which allows
a process to set or change the set of processes it is allowed to share a
core with.

This proc file is intended to help with introspection and testing to
determine which other processes does it share a core with.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
3 files changed