From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: netdev@vger.kernel.org, lp2s1h@gmail.com
Subject: Re: [PATCH] codel: refine one condition to avoid a nul rec_inv_sqrt
Date: Mon, 30 Jul 2012 14:54:12 -0700 (PDT) [thread overview]
Message-ID: <20120730.145412.1689803770003231369.davem@davemloft.net> (raw)
In-Reply-To: <1343631141.2626.13293.camel@edumazet-glaptop>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 30 Jul 2012 08:52:21 +0200
> From: Eric Dumazet <edumazet@google.com>
>
> One condition before codel_Newton_step() was not good if
> we never left the dropping state for a flow. As a result
> rec_inv_sqrt was 0, instead of the ~0 initial value.
>
> codel control law was then set to a very aggressive mode, dropping
> many packets before reaching 'target' and recovering from this problem.
>
> To keep codel_vars_init() as efficient as possible, refine
> the condition to make sure rec_inv_sqrt initial value is correct
>
> Many thanks to Anton Mich for discovering the issue and suggesting
> a fix.
>
> Reported-by: Anton Mich <lp2s1h@gmail.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Applied and queued up for -stable.
next prev parent reply other threads:[~2012-07-30 21:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-30 6:52 [PATCH] codel: refine one condition to avoid a nul rec_inv_sqrt Eric Dumazet
2012-07-30 21:54 ` David Miller [this message]
2012-08-10 15:16 ` Eric Dumazet
2012-08-10 23:54 ` David Miller
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