From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>
Cc: "Neal Cardwell" <ncardwell@google.com>,
"David Miller" <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
"Tom Herbert" <therbert@google.com>,
"Maciej Żenczykowski" <maze@google.com>,
"Yuchung Cheng" <ycheng@google.com>
Subject: Re: [PATCH v2 net-next] tcp: avoid expensive pskb_expand_head() calls
Date: Thu, 19 Apr 2012 14:44:50 +0200 [thread overview]
Message-ID: <1334839490.2395.160.camel@edumazet-glaptop> (raw)
In-Reply-To: <alpine.DEB.2.00.1204191443040.735@wel-95.cs.helsinki.fi>
On Thu, 2012-04-19 at 14:57 +0300, Ilpo Järvinen wrote:
> I'm not concerned of the output side, that seems to work because
> of the in tcp_retransmit_skb getting rid of the extra first.
>
> The ACK input stuff is more interesting, e.g., this one in
> tcp_mark_head_lost:
>
> err = tcp_fragment(sk, skb, (packets - oldcnt) * mss, mss);
>
> It splits from TCP_SKB_CB(skb)->seq + (packets - oldcnt) * mss whereas
> I think the desired point would be: TCP_SKB_CB(skb)->seq + offset_ack +
> (packets - oldcnt) * mss?
>
> ...There is similar case in sacktag code too while it's aligning to mss
> boundaries in tcp_match_skb_to_sack.
Hmm yes, so maybe its safer to update TCP_SKB_CB(skb)->seq in
tcp_tso_acked() (as well as offset_ack) and make needed adjustements in
tcp_fragment() if we find offset_ack being not null.
next prev parent reply other threads:[~2012-04-19 12:44 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-17 9:06 [BUG] ixgbe: something wrong with queue selection ? Eric Dumazet
2012-04-17 9:16 ` Jeff Kirsher
2012-04-17 16:01 ` Alexander Duyck
2012-04-17 16:38 ` John Fastabend
2012-04-17 17:07 ` Ben Hutchings
2012-04-17 16:46 ` Eric Dumazet
2012-04-17 21:38 ` TSO not 10G friendly if peer is close enough Eric Dumazet
2012-04-17 21:47 ` David Miller
2012-04-18 3:00 ` Eric Dumazet
2012-04-18 15:49 ` [PATCH net-next] tcp: avoid expensive pskb_expand_head() calls Eric Dumazet
[not found] ` <4F8EF317.10504@hp.com>
2012-04-18 17:16 ` Eric Dumazet
2012-04-18 17:30 ` Rick Jones
2012-04-18 17:40 ` Eric Dumazet
2012-04-18 18:40 ` Neal Cardwell
2012-04-18 19:18 ` Eric Dumazet
2012-04-18 19:51 ` [PATCH v2 " Eric Dumazet
2012-04-19 11:10 ` Ilpo Järvinen
2012-04-19 11:30 ` Eric Dumazet
2012-04-19 11:40 ` Eric Dumazet
2012-04-19 11:57 ` Ilpo Järvinen
2012-04-19 12:44 ` Eric Dumazet [this message]
2012-04-20 12:27 ` Ilpo Järvinen
2012-04-19 13:18 ` Eric Dumazet
2012-04-19 13:52 ` Eric Dumazet
2012-04-19 14:10 ` Eric Dumazet
2012-04-19 17:20 ` Rick Jones
2012-04-19 17:25 ` Eric Dumazet
2012-04-19 17:48 ` Rick Jones
2012-04-19 18:00 ` Eric Dumazet
2012-04-19 18:05 ` Rick Jones
2012-04-18 19:41 ` [PATCH " Vijay Subramanian
2012-04-18 19:49 ` Eric Dumazet
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