From a3b18ddb9cc1056eea24e3edc1828cfb3fd0726f Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 1 Jul 2014 21:33:17 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/linux/skbuff.h | 9 +++++++-- net/core/flow_dissector.c | 2 ++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index b297af70ac30..890fb3307dd6 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -455,6 +455,7 @@ static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1, * @ooo_okay: allow the mapping of a socket to a queue to be changed * @l4_hash: indicate hash is a canonical 4-tuple hash over transport * ports. + * @sw_hash: indicates hash was computed in software stack * @wifi_acked_valid: wifi_acked was set * @wifi_acked: whether frame was acked on wifi or not * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS @@ -562,6 +563,7 @@ struct sk_buff { __u8 pfmemalloc:1; __u8 ooo_okay:1; __u8 l4_hash:1; + __u8 sw_hash:1; __u8 wifi_acked_valid:1; __u8 wifi_acked:1; __u8 no_fcs:1; @@ -575,7 +577,7 @@ struct sk_buff { __u8 encap_hdr_csum:1; __u8 csum_valid:1; __u8 csum_complete_sw:1; - /* 3/5 bit hole (depending on ndisc_nodetype presence) */ + /* 2/4 bit hole (depending on ndisc_nodetype presence) */ kmemcheck_bitfield_end(flags2); #if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL @@ -830,13 +832,14 @@ static inline void skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type) { skb->l4_hash = (type == PKT_HASH_TYPE_L4); + skb->sw_hash = 0; skb->hash = hash; } void __skb_get_hash(struct sk_buff *skb); static inline __u32 skb_get_hash(struct sk_buff *skb) { - if (!skb->l4_hash) + if (!skb->l4_hash && !skb->sw_hash) __skb_get_hash(skb); return skb->hash; @@ -850,6 +853,7 @@ static inline __u32 skb_get_hash_raw(const struct sk_buff *skb) static inline void skb_clear_hash(struct sk_buff *skb) { skb->hash = 0; + skb->sw_hash = 0; skb->l4_hash = 0; } @@ -862,6 +866,7 @@ static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb) static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from) { to->hash = from->hash; + to->sw_hash = from->sw_hash; to->l4_hash = from->l4_hash; }; diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index c5f3912dad4c..5f362c1d0332 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -256,6 +256,8 @@ void __skb_get_hash(struct sk_buff *skb) if (keys.ports) skb->l4_hash = 1; + skb->sw_hash = 1; + skb->hash = __flow_hash_from_keys(&keys); } EXPORT_SYMBOL(__skb_get_hash); -- 2.20.1