Messages in this thread | | | Date | Fri, 21 Nov 2008 16:43:40 -0800 (PST) | Subject | Re: [PATCH] Do not use TSO/GSO when there is urgent data | From | David Miller <> |
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From: Petr Tesarik <ptesarik@suse.cz> Date: Fri, 21 Nov 2008 13:19:45 +0100
> This patch fixes http://bugzilla.kernel.org/show_bug.cgi?id=12014 > > Since most (if not all) implementations of TSO and even the in-kernel > software GSO do not update the urgent pointer when splitting a large > segment, it is necessary to turn off TSO/GSO for all outgoing traffic > with the URG pointer set. > > Looking at tcp_current_mss (and the preceding comment) I even think > this was the original intention. However, this approach is insufficient, > because TSO/GSO is turned off only for newly created frames, not for > frames which were already pending at the arrival of a message with > MSG_OOB set. These frames were created when TSO/GSO was enabled, > so they may be large, and they will have the urgent pointer set > in tcp_transmit_skb(). > > With this patch, such large packets will be fragmented again before > going to the transmit routine. > > As a side note, at least the following NICs are known to screw up > the urgent pointer in the TCP header when doing TSO: > > Intel 82566MM (PCI ID 8086:1049) > Intel 82566DC (PCI ID 8086:104b) > Intel 82541GI (PCI ID 8086:1076) > Broadcom NetXtreme II BCM5708 (PCI ID 14e4:164c) > > Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Applied, thanks Petr.
BTW, your email client screwed up the patch by breaking up long lines, for example:
> @@ -722,7 +722,8 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff > *skb)
And:
> @@ -1163,7 +1164,9 @@ static int tcp_init_tso_segs(struct sock *sk, struct > sk_buff *skb,
I fixed it up this time, but I will not in the future.
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