Re: [PATCH] tcp: don't use timestamp from repaired skb-s to calculate RTT (v2)

From: David Miller
Date: Thu Aug 14 2014 - 17:39:41 EST

From: Andrey Vagin <avagin@xxxxxxxxxx>
Date: Wed, 13 Aug 2014 16:03:10 +0400

> We don't know right timestamp for repaired skb-s. Wrong RTT estimations
> isn't good, because some congestion modules heavily depends on it.
> This patch adds the TCPCB_REPAIRED flag, which is included in
> Thanks to Eric for the advice how to fix this issue.
> This patch fixes the warning:
> v2: moving setting of skb->when for repaired skb-s in tcp_write_xmit,
> where it's set for other skb-s.
> Fixes: 431a91242d8d ("tcp: timestamp SYN+DATA messages")
> Fixes: 740b0f1841f6 ("tcp: switch rtt estimations to usec resolution")
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Signed-off-by: Andrey Vagin <avagin@xxxxxxxxxx>

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