From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH 1/1] tcp: Honor the eor bit in tcp_mtu_probe Date: Mon, 05 Feb 2018 09:10:19 -0800 Message-ID: <1517850619.3715.144.camel@gmail.com> References: <20180205151126.77495-1-ilyal@mellanox.com> <1517845948.3715.142.camel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Cc: borisp@mellanox.com To: Ilya Lesokhin , netdev@vger.kernel.org, kafai@fb.com Return-path: Received: from mail-pg0-f65.google.com ([74.125.83.65]:39534 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752582AbeBERKW (ORCPT ); Mon, 5 Feb 2018 12:10:22 -0500 Received: by mail-pg0-f65.google.com with SMTP id w17so19069662pgv.6 for ; Mon, 05 Feb 2018 09:10:21 -0800 (PST) In-Reply-To: <1517845948.3715.142.camel@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2018-02-05 at 07:52 -0800, Eric Dumazet wrote: > On Mon, 2018-02-05 at 17:11 +0200, Ilya Lesokhin wrote: > > Avoid SKB coalescing if eor bit is set in one of the relevant > > SKBs. > > > > Fixes: c134ecb87817 ("tcp: Make use of MSG_EOR in tcp_sendmsg") > > Signed-off-by: Ilya Lesokhin > > --- > > Reviewed-by: Eric Dumazet > > Thanks. I am taking this approval back. You missed an eor propagation if it is in the last skb that is copied to the new skb. Something like this added to your patch : diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index e9f985e42405a38fc95980da5debb7ac8b51fbb5..87c2ff458f7528ee3cd3e5e1154375a906c1bc67 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2134,6 +2134,7 @@ static int tcp_mtu_probe(struct sock *sk)   /* We've eaten all the data from this skb.    * Throw it away. */   TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; + TCP_SKB_CB(nskb)->eor = TCP_SKB_CB(skb)->eor;   tcp_unlink_write_queue(skb, sk);   sk_wmem_free_skb(sk, skb);   } else {