Re: [PATCH 7/7] netprio_cgroup: allow nesting and inherit config on cgroup creation
From: Daniel Wagner <hidden>
Date: 2012-11-20 08:57:18
Also in:
lkml, netdev
Hi Tejun, On 20.11.2012 09:30, Tejun Heo wrote:
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 <redacted>
Tested and Acked-by: Daniel Wagner [off-list ref]
quoted hunk ↗ jump to hunk
--- Documentation/cgroups/net_prio.txt | 2 ++ net/core/netprio_cgroup.c | 42 ++++++++++++++++++++++---------------- 2 files changed, 26 insertions(+), 18 deletions(-)diff --git a/Documentation/cgroups/net_prio.txt b/Documentation/cgroups/net_prio.txt index 01b3226..a82cbd2 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.diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index b2af0d0..bde53da 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c@@ -136,9 +136,6 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) { struct cgroup_netprio_state *cs; - if (cgrp->parent && cgrp->parent->id) - return ERR_PTR(-EINVAL); - cs = kzalloc(sizeof(*cs), GFP_KERNEL); if (!cs) return ERR_PTR(-ENOMEM);@@ -146,16 +143,34 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) return &cs->css; } -static void cgrp_css_free(struct cgroup *cgrp) +static int cgrp_css_online(struct cgroup *cgrp) { - struct cgroup_netprio_state *cs = cgrp_netprio_state(cgrp); + struct cgroup *parent = cgrp->parent; struct net_device *dev; + int ret = 0; + + if (!parent) + return 0;
BTW, parent is always != NULL, because the root cgroup will be attached
to the dummytop cgroup.
This is the reason why there are this check in netprio_prio()
static u32 netprio_prio(struct cgroup *cgrp, struct net_device *dev)
{
struct netprio_map *map = rcu_dereference_rtnl(dev->priomap);
if (map && cgrp->id < map->priomap_len)
return map->priomap[cgrp->id];
is necessary.
cheer,
daniel