Date: Sun, 08 May 2011 15:52:15 -0700 (PDT)
Message-Id: <20110508.155215.242144177.davem@davemloft.net>
To: shemminger@vyatta.com
Cc: sangtae.ha@gmail.com, injongrhee@gmail.com, Valdis.Kletnieks@vt.edu,
        rdunlap@xenotime.net, lkml@techboom.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tcp_cubic: limit delayed_ack ratio to prevent divide
 error
From: David Miller <davem@davemloft.net>
In-Reply-To: <20110504130456.425dee68@nehalam>
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	<20110504.124053.260068550.davem@davemloft.net>
	<20110504130456.425dee68@nehalam>
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From: Stephen Hemminger <shemminger@vyatta.com>
Date: Wed, 4 May 2011 13:04:56 -0700

> TCP Cubic keeps a metric that estimates the amount of delayed
> acknowledgements to use in adjusting the window. If an abnormally
> large number of packets are acknowledged at once, then the update
> could wrap and reach zero. This kind of ACK could only
> happen when there was a large window and huge number of
> ACK's were lost.
> 
> This patch limits the value of delayed ack ratio. The choice of 32
> is just a conservative value since normally it should be range of 
> 1 to 4 packets.
> 
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

Applied, thanks Stephen.
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