From 5eddb24901ee49eee23c0bfce6af2e83fd5679bd Mon Sep 17 00:00:00 2001
From: Coco Li <lixiaoyan@google.com>
Date: Fri, 30 Sep 2022 15:09:05 -0700
Subject: gro: add support of (hw)gro packets to gro stack
Current GRO stack only supports incoming packets containing
one frame/MSS.
This patch changes GRO to accept packets that are already GRO.
HW-GRO (aka RSC for some vendors) is very often limited in presence
of interleaved packets. Linux SW GRO stack can complete the job
and provide larger GRO packets, thus reducing rate of ACK packets
and cpu overhead.
This also means BIG TCP can still be used, even if HW-GRO/RSC was
able to cook ~64 KB GRO packets.
v2: fix logic in tcp_gro_receive()
Only support TCP for the moment (Paolo)
Co-Developed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Coco Li <lixiaoyan@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/core/gro.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
(limited to 'net/core/gro.c')
diff --git a/net/core/gro.c b/net/core/gro.c
index b4190eb08467..bc9451743307 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -160,6 +160,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
unsigned int gro_max_size;
unsigned int new_truesize;
struct sk_buff *lp;
+ int segs;
/* pairs with WRITE_ONCE() in netif_set_gro_max_size() */
gro_max_size = READ_ONCE(p->dev->gro_max_size);
@@ -175,6 +176,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
return -E2BIG;
}
+ segs = NAPI_GRO_CB(skb)->count;
lp = NAPI_GRO_CB(p)->last;
pinfo = skb_shinfo(lp);
@@ -265,7 +267,7 @@ merge:
lp = p;
done:
- NAPI_GRO_CB(p)->count++;
+ NAPI_GRO_CB(p)->count += segs;
p->data_len += len;
p->truesize += delta_truesize;
p->len += len;
@@ -496,8 +498,15 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed),
sizeof(u32))); /* Avoid slow unaligned acc */
*(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0;
- NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
+ NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb);
NAPI_GRO_CB(skb)->is_atomic = 1;
+ NAPI_GRO_CB(skb)->count = 1;
+ if (unlikely(skb_is_gso(skb))) {
+ NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs;
+ /* Only support TCP at the moment. */
+ if (!skb_is_gso_tcp(skb))
+ NAPI_GRO_CB(skb)->flush = 1;
+ }
/* Setup for GRO checksum validation */
switch (skb->ip_summed) {
@@ -545,10 +554,10 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
else
gro_list->count++;
- NAPI_GRO_CB(skb)->count = 1;
NAPI_GRO_CB(skb)->age = jiffies;
NAPI_GRO_CB(skb)->last = skb;
- skb_shinfo(skb)->gso_size = skb_gro_len(skb);
+ if (!skb_is_gso(skb))
+ skb_shinfo(skb)->gso_size = skb_gro_len(skb);
list_add(&skb->list, &gro_list->list);
ret = GRO_HELD;
@@ -660,6 +669,7 @@ static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
skb->encapsulation = 0;
skb_shinfo(skb)->gso_type = 0;
+ skb_shinfo(skb)->gso_size = 0;
if (unlikely(skb->slow_gro)) {
skb_orphan(skb);
skb_ext_reset(skb);
--
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