| Message ID | 1412989595.9362.30.camel@edumazet-glaptop2.roam.corp.google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Fri, 10 Oct 2014 18:06:35 -0700 > From: Eric Dumazet <edumazet@google.com> > > TCP Small Queues (tcp_tsq_handler()) can hold one reference on > sk->sk_wmem_alloc, preventing skb->ooo_okay being set. > > We should relax test done to set skb->ooo_okay to take care > of this extra reference. > > Minimal truesize of skb containing one byte of payload is > SKB_TRUESIZE(1) > > Without this fix, we have more chance locking flows into the wrong > transmit queue. > > Signed-off-by: Eric Dumazet <edumazet@google.com> Applied, thanks Eric. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 8d4eac793700..e2be1f80e0be 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -914,9 +914,13 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, tcp_ca_event(sk, CA_EVENT_TX_START); /* if no packet is in qdisc/device queue, then allow XPS to select - * another queue. + * another queue. We can be called from tcp_tsq_handler() + * which holds one reference to sk_wmem_alloc. + * + * TODO: Ideally, in-flight pure ACK packets should not matter here. + * One way to get this would be to set skb->truesize = 2 on them. */ - skb->ooo_okay = sk_wmem_alloc_get(sk) == 0; + skb->ooo_okay = sk_wmem_alloc_get(sk) < SKB_TRUESIZE(1); skb_push(skb, tcp_header_size); skb_reset_transport_header(skb);