netprio_cgroup: allow nesting and inherit config on cgroup creation

Inherit netprio configuration from ->css_online(), allow nesting and
remove .broken_hierarchy marking.  This makes netprio_cgroup's
behavior match netcls_cgroup's.

Note that this patch changes userland-visible behavior.  Nesting is
allowed and the first level cgroups below the root cgroup behave
differently - they inherit priorities from the root cgroup on creation
instead of starting with 0.  This is unfortunate but not doing so is
much crazier.

Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-and-Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/Documentation/cgroups/net_prio.txt b/Documentation/cgroups/net_prio.txt
index 01b322635591..a82cbd28ea8a 100644
--- a/Documentation/cgroups/net_prio.txt
+++ b/Documentation/cgroups/net_prio.txt
@@ -51,3 +51,5 @@ One usage for the net_prio cgroup is with mqprio qdisc allowing application
 traffic to be steered to hardware/driver based traffic classes. These mappings
 can then be managed by administrators or other networking protocols such as
 DCBX.
+
+A new net_prio cgroup inherits the parent's configuration.