tree 3ca6bea6ada80291da7ae5713ef5f36aed2785b3
parent b0af004fd58ded5f898630db008c5b824c27d7db
author Tejun Heo <tj@kernel.org> 1559324338 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1565366016 +0200

cgroup: Include dying leaders with live threads in PROCS iterations

commit c03cd7738a83b13739f00546166969342c8ff014 upstream.

CSS_TASK_ITER_PROCS currently iterates live group leaders; however,
this means that a process with dying leader and live threads will be
skipped.  IOW, cgroup.procs might be empty while cgroup.threads isn't,
which is confusing to say the least.

Fix it by making cset track dying tasks and include dying leaders with
live threads in PROCS iteration.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Topi Miettinen <toiwoton@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>