From 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 30 Aug 2017 14:30:36 -0700 Subject: net_sched: add reverse binding for tc class TC filters when used as classifiers are bound to TC classes. However, there is a hidden difference when adding them in different orders: 1. If we add tc classes before its filters, everything is fine. Logically, the classes exist before we specify their ID's in filters, it is easy to bind them together, just as in the current code base. 2. If we add tc filters before the tc classes they bind, we have to do dynamic lookup in fast path. What's worse, this happens all the time not just once, because on fast path tcf_result is passed on stack, there is no way to propagate back to the one in tc filters. This hidden difference hurts performance silently if we have many tc classes in hierarchy. This patch intends to close this gap by doing the reverse binding when we create a new class, in this case we can actually search all the filters in its parent, match and fixup by classid. And because tcf_result is specific to each type of tc filter, we have to introduce a new ops for each filter to tell how to bind the class. Note, we still can NOT totally get rid of those class lookup in ->enqueue() because cgroup and flow filters have no way to determine the classid at setup time, they still have to go through dynamic lookup. Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/cls_fw.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'net/sched/cls_fw.c') diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c index 192255ec50bd..941245ad07fd 100644 --- a/net/sched/cls_fw.c +++ b/net/sched/cls_fw.c @@ -412,6 +412,14 @@ nla_put_failure: return -1; } +static void fw_bind_class(void *fh, u32 classid, unsigned long cl) +{ + struct fw_filter *f = fh; + + if (f && f->res.classid == classid) + f->res.class = cl; +} + static struct tcf_proto_ops cls_fw_ops __read_mostly = { .kind = "fw", .classify = fw_classify, @@ -422,6 +430,7 @@ static struct tcf_proto_ops cls_fw_ops __read_mostly = { .delete = fw_delete, .walk = fw_walk, .dump = fw_dump, + .bind_class = fw_bind_class, .owner = THIS_MODULE, }; -- cgit v1.2.3-59-g8ed1b