[PATCH net-next 2/4] gro: don't dereference napi->gro_hash[x] multiple times in dev_gro_receive()
From: Alexander Lobakin <hidden>
Date: 2021-03-12 16:22:53
Also in:
lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
GRO bucket index doesn't change through the entire function. Store a pointer to the corresponding bucket on stack once and use it later instead of dereferencing again and again. Signed-off-by: Alexander Lobakin <redacted> --- net/core/dev.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index adc42ba7ffd8..ee124aecb8a2 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -5957,6 +5957,7 @@ static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head) static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb) { u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1); + struct gro_list *gro_list = &napi->gro_hash[bucket]; struct list_head *head = &offload_base; struct packet_offload *ptype; __be16 type = skb->protocol;
@@ -6024,7 +6025,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff if (pp) { skb_list_del_init(pp); napi_gro_complete(napi, pp); - napi->gro_hash[bucket].count--; + gro_list->count--; } if (same_flow)
@@ -6033,10 +6034,10 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff if (NAPI_GRO_CB(skb)->flush) goto normal; - if (unlikely(napi->gro_hash[bucket].count >= MAX_GRO_SKBS)) { + if (unlikely(gro_list->count >= MAX_GRO_SKBS)) { gro_flush_oldest(napi, gro_head); } else { - napi->gro_hash[bucket].count++; + gro_list->count++; } NAPI_GRO_CB(skb)->count = 1; NAPI_GRO_CB(skb)->age = jiffies;
@@ -6050,7 +6051,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff if (grow > 0) gro_pull_from_frag0(skb, grow); ok: - if (napi->gro_hash[bucket].count) { + if (gro_list->count) { if (!test_bit(bucket, &napi->gro_bitmask)) __set_bit(bucket, &napi->gro_bitmask); } else if (test_bit(bucket, &napi->gro_bitmask)) { --
2.30.2