From: Toke Høiland-Jørgensen toke@redhat.com
[ Upstream commit 8c95eca0bb8c4bd2231a0d581f1ad0d50c90488c ]
As a further optimisation of the diffserv parsing codepath, we can skip it entirely if CAKE is configured to neither use diffserv-based classification, nor to zero out the diffserv bits.
Fixes: c87b4ecdbe8d ("sch_cake: Make sure we can write the IP header before changing DSCP bits") Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_cake.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 8020d0829f1a9..e1b93ff79ab53 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1515,7 +1515,7 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free) return idx + (tin << 16); }
-static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash) +static u8 cake_handle_diffserv(struct sk_buff *skb, bool wash) { const int offset = skb_network_offset(skb); u16 *buf, buf_; @@ -1576,14 +1576,17 @@ static struct cake_tin_data *cake_select_tin(struct Qdisc *sch, { struct cake_sched_data *q = qdisc_priv(sch); u32 tin, mark; + bool wash; u8 dscp;
/* Tin selection: Default to diffserv-based selection, allow overriding - * using firewall marks or skb->priority. + * using firewall marks or skb->priority. Call DSCP parsing early if + * wash is enabled, otherwise defer to below to skip unneeded parsing. */ - dscp = cake_handle_diffserv(skb, - q->rate_flags & CAKE_FLAG_WASH); mark = (skb->mark & q->fwmark_mask) >> q->fwmark_shft; + wash = !!(q->rate_flags & CAKE_FLAG_WASH); + if (wash) + dscp = cake_handle_diffserv(skb, wash);
if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT) tin = 0; @@ -1597,6 +1600,8 @@ static struct cake_tin_data *cake_select_tin(struct Qdisc *sch, tin = q->tin_order[TC_H_MIN(skb->priority) - 1];
else { + if (!wash) + dscp = cake_handle_diffserv(skb, wash); tin = q->tin_index[dscp];
if (unlikely(tin >= q->tin_cnt))