netdev - Re: [PATCH net-next] tcp: autocork: take MSG

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACSApvZ1wyP6vRFujZOxwF1277OwHmLsxa6Hi-gFt9xzKnuCwA@mail.gmail.com>
Date:   Wed, 9 Mar 2022 09:13:15 -0500
From:   Soheil Hassas Yeganeh <soheil@...gle.com>
To:     Eric Dumazet <eric.dumazet@...il.com>
Cc:     "David S . Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        netdev <netdev@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Martin KaFai Lau <kafai@...com>,
        Willem de Bruijn <willemb@...gle.com>
Subject: Re: [PATCH net-next] tcp: autocork: take MSG_EOR hint into consideration

On Wed, Mar 9, 2022 at 12:47 AM Eric Dumazet <eric.dumazet@...il.com> wrote:
>
> From: Eric Dumazet <edumazet@...gle.com>
>
> tcp_should_autocork() is evaluating if it makes senses
> to not immediately send current skb, hoping that
> user space will add more payload on it by the
> time TCP stack reacts to upcoming TX completions.
>
> If current skb got MSG_EOR mark, then we know
> that no further data will be added, it is therefore
> futile to wait.
>
> SOF_TIMESTAMPING_TX_ACK will become a bit more accurate,
> if prior packets are still in qdisc/device queues.
>
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> Cc: Martin KaFai Lau <kafai@...com>
> Cc: Soheil Hassas Yeganeh <soheil@...gle.com>
> Cc: Willem de Bruijn <willemb@...gle.com>

Acked-by: Soheil Hassas Yeganeh <soheil@...gle.com>

Thanks for catching this!

> ---
>  net/ipv4/tcp.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 33f20134e3f19c1cd8a4046a2f88533693a9a912..b6a03a121e7694e3e8cc5b4f47b7954a341c966e 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -688,7 +688,8 @@ static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
>         return skb->len < size_goal &&
>                sock_net(sk)->ipv4.sysctl_tcp_autocorking &&
>                !tcp_rtx_queue_empty(sk) &&
> -              refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
> +              refcount_read(&sk->sk_wmem_alloc) > skb->truesize &&
> +              tcp_skb_can_collapse_to(skb);
>  }
>
>  void tcp_push(struct sock *sk, int flags, int mss_now,
> --
> 2.35.1.616.g0bdcbb4464-goog
>