netprio_cgroup: implement hierarchy support
Implement hierarchy support. Each netprio_cgroup inherits its
parent's prio config for any net_device which it doesn't have local
config on.
As each netprio_cgroup is fully ready after ->css_alloc() and config
inheritance doesn't affect the parent, netprio_cgroup doesn't need to
strictly distinguish on and offline cgroups and can get by simply
inheriting the parent's configuration from ->css_online() and
propagating config updates downwards in write_priomap().
* As ->css_online() inherits prios on all netdevs from the parent,
clearing priomap on ->css_free() is no longer necessary. Removed.
* Error out on nesting in ->css_alloc() removed along with
ss->broken_hierarchy marking.
Note that this patch changes userland-visible behavior. Nesting is
now allowed and priority configuration is inherited through hierarchy.
This especially changes how the first level cgroups below the root
cgroup behave - any unconfigured pairs now inherit priorities from the
root cgroup instead of assuming 0.
Signed-off-by: Tejun Heo <tj@kernel.org>
2 files changed
