diff options
| author | Coco Li <lixiaoyan@google.com> | 2022-09-30 15:09:05 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-10-03 12:38:34 +0100 |
| commit | 5eddb24901ee49eee23c0bfce6af2e83fd5679bd (patch) | |
| tree | d6d3b37a6a5c040641259b5082b73beb3d2ee7b9 /net/ipv4 | |
| parent | 197060c155106c48b2f35b0c1306c1b1d320a47a (diff) | |
| download | lwn-5eddb24901ee49eee23c0bfce6af2e83fd5679bd.tar.gz lwn-5eddb24901ee49eee23c0bfce6af2e83fd5679bd.zip | |
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>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_offload.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index a844a0d38482..45dda7889387 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -255,7 +255,15 @@ found: mss = skb_shinfo(p)->gso_size; - flush |= (len - 1) >= mss; + /* If skb is a GRO packet, make sure its gso_size matches prior packet mss. + * If it is a single frame, do not aggregate it if its length + * is bigger than our mss. + */ + if (unlikely(skb_is_gso(skb))) + flush |= (mss != skb_shinfo(skb)->gso_size); + else + flush |= (len - 1) >= mss; + flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); #ifdef CONFIG_TLS_DEVICE flush |= p->decrypted ^ skb->decrypted; @@ -269,7 +277,12 @@ found: tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); out_check_final: - flush = len < mss; + /* Force a flush if last segment is smaller than mss. */ + if (unlikely(skb_is_gso(skb))) + flush = len != NAPI_GRO_CB(skb)->count * skb_shinfo(skb)->gso_size; + else + flush = len < mss; + flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | TCP_FLAG_RST | TCP_FLAG_SYN | TCP_FLAG_FIN)); |