[PATCH 5.4 086/129] net: core: use listified Rx for GRO_NORMAL in napi_gro_receive()

From: Greg Kroah-Hartman
Date: Tue Sep 08 2020 - 15:51:54 EST


From: Alexander Lobakin <alobakin@xxxxxxxx>

commit 6570bc79c0dfff0f228b7afd2de720fb4e84d61d upstream.

Commit 323ebb61e32b4 ("net: use listified RX for handling GRO_NORMAL
skbs") made use of listified skb processing for the users of
napi_gro_frags().
The same technique can be used in a way more common napi_gro_receive()
to speed up non-merged (GRO_NORMAL) skbs for a wide range of drivers
including gro_cells and mac80211 users.
This slightly changes the return value in cases where skb is being
dropped by the core stack, but it seems to have no impact on related
drivers' functionality.
gro_normal_batch is left untouched as it's very individual for every
single system configuration and might be tuned in manual order to
achieve an optimal performance.

Signed-off-by: Alexander Lobakin <alobakin@xxxxxxxx>
Acked-by: Edward Cree <ecree@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Hyunsoon Kim <h10.kim@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/core/dev.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5602,12 +5602,13 @@ static void napi_skb_free_stolen_head(st
kmem_cache_free(skbuff_head_cache, skb);
}

-static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
+static gro_result_t napi_skb_finish(struct napi_struct *napi,
+ struct sk_buff *skb,
+ gro_result_t ret)
{
switch (ret) {
case GRO_NORMAL:
- if (netif_receive_skb_internal(skb))
- ret = GRO_DROP;
+ gro_normal_one(napi, skb);
break;

case GRO_DROP:
@@ -5639,7 +5640,7 @@ gro_result_t napi_gro_receive(struct nap

skb_gro_reset_offset(skb);

- ret = napi_skb_finish(dev_gro_receive(napi, skb), skb);
+ ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb));
trace_napi_gro_receive_exit(ret);

return ret;