sch_sfb: use skb_flow_dissect()
Current SFB double hashing is not fulfilling SFB theory, if two flows
share same rxhash value.
Using skb_flow_dissect() permits to really have better hash dispersion,
and get tunnelling support as well.
Double hashing point was mentioned by Florian Westphal
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index e83c272..96e42ca 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -26,6 +26,7 @@
#include <net/ip.h>
#include <net/pkt_sched.h>
#include <net/inet_ecn.h>
+#include <net/flow_keys.h>
/*
* SFB uses two B[l][n] : L x N arrays of bins (L levels, N bins per level)
@@ -286,6 +287,7 @@
u32 minqlen = ~0;
u32 r, slot, salt, sfbhash;
int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+ struct flow_keys keys;
if (unlikely(sch->q.qlen >= q->limit)) {
sch->qstats.overlimits++;
@@ -309,13 +311,19 @@
/* If using external classifiers, get result and record it. */
if (!sfb_classify(skb, q, &ret, &salt))
goto other_drop;
+ keys.src = salt;
+ keys.dst = 0;
+ keys.ports = 0;
} else {
- salt = skb_get_rxhash(skb);
+ skb_flow_dissect(skb, &keys);
}
slot = q->slot;
- sfbhash = jhash_1word(salt, q->bins[slot].perturbation);
+ sfbhash = jhash_3words((__force u32)keys.dst,
+ (__force u32)keys.src,
+ (__force u32)keys.ports,
+ q->bins[slot].perturbation);
if (!sfbhash)
sfbhash = 1;
sfb_skb_cb(skb)->hashes[slot] = sfbhash;
@@ -347,7 +355,10 @@
if (unlikely(p_min >= SFB_MAX_PROB)) {
/* Inelastic flow */
if (q->double_buffering) {
- sfbhash = jhash_1word(salt, q->bins[slot].perturbation);
+ sfbhash = jhash_3words((__force u32)keys.dst,
+ (__force u32)keys.src,
+ (__force u32)keys.ports,
+ q->bins[slot].perturbation);
if (!sfbhash)
sfbhash = 1;
sfb_skb_cb(skb)->hashes[slot] = sfbhash;