From: Eric Dumazet <edumazet@google.com>
Date: Mon, 6 Jul 2015 12:18:09 +0000 (-0700)
Subject: net_sched: act_mirred: remove spinlock in fast path
X-Git-Tag: omap-for-v4.3/fixes-rc1~110^2~397^2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2ee22a90c7afac265bb6f7abea610b938195e2b8;p=pandora-kernel.git

net_sched: act_mirred: remove spinlock in fast path

Like act_gact, act_mirred can be lockless in packet processing

1) Use percpu stats
2) update lastuse only every clock tick to avoid false sharing
3) use rcu to protect tcfm_dev
4) Remove spinlock usage, as it is no longer needed.

Next step : add multi queue capability to ifb device

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/net/tc_act/tc_mirred.h b/include/net/tc_act/tc_mirred.h
index 4dd77a1c106b..dae96bae1c19 100644
--- a/include/net/tc_act/tc_mirred.h
+++ b/include/net/tc_act/tc_mirred.h
@@ -8,7 +8,7 @@ struct tcf_mirred {
 	int			tcfm_eaction;
 	int			tcfm_ifindex;
 	int			tcfm_ok_push;
-	struct net_device	*tcfm_dev;
+	struct net_device __rcu	*tcfm_dev;
 	struct list_head	tcfm_list;
 };
 #define to_mirred(a) \
Reading git-diff-tree failed