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From: Baruch Even <baruch@ev-en.org>
To: John Heffner <jheffner@psc.edu>
Cc: "David S. Miller" <davem@davemloft.net>,
	shemminger@osdl.org, netdev@oss.sgi.com, werner@almesberger.net
Subject: Re: [PATCH] Too aggressive cwnd backoff
Date: Fri, 08 Apr 2005 22:33:58 +0100	[thread overview]
Message-ID: <4256F8C6.40704@ev-en.org> (raw)
In-Reply-To: <Pine.LNX.4.58.0504071435450.17545@dexter.psc.edu>

John Heffner wrote:
> This test looks correct to me.  (We never touched it.)  It is the bounding
> parameter specified in rate halving.  If you actually get down that far,
> then rate halving is getting confused, though.

In my tests with either NewReno at high-BDP network settings
(300Kbit/s, 120ms delay, BDP = 3200 packets), we always go into this
confused mode.

It will always upon a drop go to a point between the one-half and 
one-quarter of the original cwnd, but then, due to performance problems 
at that point the queue is filled and lots of packets are getting lost 
in bursts after I disabled throttling, with throttling it goes even 
below one quarter.

If I understand you correctly this check (that I changed) is correct and 
should not be changed but rather that the bug is elsewhere. I'll give it 
another look when I have some more time.

Baruch

  reply	other threads:[~2005-04-08 21:33 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-04-07 16:41 [PATCH] Too aggressive cwnd backoff Baruch Even
2005-04-07 17:16 ` Stephen Hemminger
2005-04-07 18:14   ` Baruch Even
2005-04-07 18:31     ` David S. Miller
2005-04-07 18:37       ` John Heffner
2005-04-08 21:33         ` Baruch Even [this message]
2005-04-07 20:26   ` Werner Almesberger
2005-04-07 18:33 ` David S. Miller
2005-04-07 19:18   ` Baruch Even
2005-04-07 20:37     ` David S. Miller
2005-04-07 21:42   ` Herbert Xu
2005-04-07 21:45     ` David S. Miller

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