From: Eric Dumazet <eduma...@google.com>
TSQ provides a nice way to avoid bufferbloat on individual socket,
including retransmit packets. We can get rid of the old
heuristic:
/* Do not sent more than we queued. 1/4 is reserved for possible
* copying overhead: fragmentation, tunneling, mangling etc.
*/
if (refcount_read(&sk->sk_wmem_alloc) >
min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2),
sk->sk_sndbuf))
return -EAGAIN;
This heuristic was giving false positives according to Jakub,
whenever TX completions are delayed above RTT. (Ack packets
are processed by TCP stack before clones are orphaned/freed)
Signed-off-by: Eric Dumazet <eduma...@google.com>
Reported-by: Jakub Kicinski <k...@kernel.org>
Cc: Neal Cardwell <ncardw...@google.com>
Cc: Yuchung Cheng <ych...@google.com>
---
net/ipv4/tcp_output.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index
0dbf208a4f2f17c630084e87f4a9a2ad0dc24168..bde781f46b41a5dd9eb8db3fb65b45d73e592b4b
100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3151,14 +3151,6 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff
*skb, int segs)
if (icsk->icsk_mtup.probe_size)
icsk->icsk_mtup.probe_size = 0;
- /* Do not sent more than we queued. 1/4 is reserved for possible
- * copying overhead: fragmentation, tunneling, mangling etc.
- */
- if (refcount_read(&sk->sk_wmem_alloc) >
- min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2),
- sk->sk_sndbuf))
- return -EAGAIN;
-
if (skb_still_in_host_queue(sk, skb))
return -EBUSY;
--
2.31.0.rc2.261.g7f71774620-goog
