path: root/net/sched/sch_sfb.c
diff options
authorWANG Cong <xiyou.wangcong@gmail.com>2017-08-24 16:51:29 -0700
committerDavid S. Miller <davem@davemloft.net>2017-08-25 17:19:10 -0700
commit143976ce992fcf3bfc0f4d15d5726bb492dcf262 (patch)
treea3f90e272ef152d3d262f1e56337d830315ba1b3 /net/sched/sch_sfb.c
parentnet_sched: introduce tclass_del_notify() (diff)
net_sched: remove tc class reference counting
For TC classes, their ->get() and ->put() are always paired, and the reference counting is completely useless, because: 1) For class modification and dumping paths, we already hold RTNL lock, so all of these ->get(),->change(),->put() are atomic. 2) For filter bindiing/unbinding, we use other reference counter than this one, and they should have RTNL lock too. 3) For ->qlen_notify(), it is special because it is called on ->enqueue() path, but we already hold qdisc tree lock there, and we hold this tree lock when graft or delete the class too, so it should not be gone or changed until we release the tree lock. Therefore, this patch removes ->get() and ->put(), but: 1) Adds a new ->find() to find the pointer to a class by classid, no refcnt. 2) Move the original class destroy upon the last refcnt into ->delete(), right after releasing tree lock. This is fine because the class is already removed from hash when holding the lock. For those who also use ->put() as ->unbind(), just rename them to reflect this change. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_sfb.c')
1 files changed, 4 insertions, 5 deletions
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index 11fb6ec878d6..cc39e170b4aa 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -632,12 +632,12 @@ static struct Qdisc *sfb_leaf(struct Qdisc *sch, unsigned long arg)
return q->qdisc;
-static unsigned long sfb_get(struct Qdisc *sch, u32 classid)
+static unsigned long sfb_find(struct Qdisc *sch, u32 classid)
return 1;
-static void sfb_put(struct Qdisc *sch, unsigned long arg)
+static void sfb_unbind(struct Qdisc *sch, unsigned long arg)
@@ -683,14 +683,13 @@ static unsigned long sfb_bind(struct Qdisc *sch, unsigned long parent,
static const struct Qdisc_class_ops sfb_class_ops = {
.graft = sfb_graft,
.leaf = sfb_leaf,
- .get = sfb_get,
- .put = sfb_put,
+ .find = sfb_find,
.change = sfb_change_class,
.delete = sfb_delete,
.walk = sfb_walk,
.tcf_block = sfb_tcf_block,
.bind_tcf = sfb_bind,
- .unbind_tcf = sfb_put,
+ .unbind_tcf = sfb_unbind,
.dump = sfb_dump_class,