net: Only do flow_dissector hash computation once per packet
Add sw_hash flag to skbuff to indicate that skb->hash was computed
from flow_dissector. This flag is checked in skb_get_hash to avoid
repeatedly trying to compute the hash (ie. in the case that no L4 hash
can be computed).
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index c5f3912..5f362c1 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -256,6 +256,8 @@
if (keys.ports)
skb->l4_hash = 1;
+ skb->sw_hash = 1;
+
skb->hash = __flow_hash_from_keys(&keys);
}
EXPORT_SYMBOL(__skb_get_hash);
