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From: "Toke Høiland-Jørgensen" <toke@toke.dk>
To: Sebastian Moeller <moeller0@gmx.de>
Cc: cake@lists.bufferbloat.net
Subject: Re: [Cake] Running Cake at long RTTs
Date: Tue, 27 Oct 2015 17:50:34 +0100	[thread overview]
Message-ID: <8737wwmf1h.fsf@toke.dk> (raw)
In-Reply-To: <6499FF74-D13B-4B2E-90E3-D1FDD3FD1468@gmx.de> (Sebastian Moeller's message of "Tue, 27 Oct 2015 17:44:05 +0100")

Sebastian Moeller <moeller0@gmx.de> writes:

>> - Turn the hard packet queue size into a lower bound rather than an
>>  upper bound.
>
> 	This seems dangerous for low memory configurations?

Well, yeah, the max packet count allowed can be higher this way, but I
guess the only sane answer to that is "don't configure cake for 100Mbit
and 1s+ of latency if you don't have the memory to spare".

Having the (now lower) bound be a bit lower than it is currently may be
a good idea, but not sure what it should be... The current 10240 matches
fq_codel.

>> - Scale the target to be 1/16th of the interval.
>
> 	Codel theory claims 5-10%, so 1/20 to 1/10, so it seems you
> 	confirm the theory, not sure why cake did not do this as a
> 	default… rem, what actually was cake setting target to? Asked
> 	differently how sensitive to target being exactly 1/16th was the
> 	throughput?

Yup. 1/16th has the benefit of being implementable as a 4bit shift :)

Before, the target was hard-coded as 5 ms; so this was definitely an
oversight.

-Toke

  parent reply	other threads:[~2015-10-27 16:50 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-27 15:14 Toke Høiland-Jørgensen
2015-10-27 15:16 ` Loganaden Velvindron
     [not found] ` <6499FF74-D13B-4B2E-90E3-D1FDD3FD1468@gmx.de>
2015-10-27 16:50   ` Toke Høiland-Jørgensen [this message]
2015-10-27 17:14     ` Sebastian Moeller
2015-10-27 19:04 ` Jonathan Morton
2015-10-27 23:57   ` Toke Høiland-Jørgensen
2015-10-28  9:36     ` Sebastian Moeller
2015-10-28 15:28 ` Sebastian Moeller
2015-10-28 15:36   ` Toke Høiland-Jørgensen
2015-10-28 15:50     ` Sebastian Moeller
2015-10-28 16:34       ` Toke Høiland-Jørgensen
2015-10-28 17:44         ` Sebastian Moeller
2015-10-29 17:36 ` Kevin Darbyshire-Bryant
2015-10-30 20:30   ` Kevin Darbyshire-Bryant
2015-10-30 21:34   ` Dave Taht

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