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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Michael Richardson <mcr@sandelman.ca>
Cc: John Crispin <blogic@openwrt.org>,
	"codel@lists.bufferbloat.net" <codel@lists.bufferbloat.net>,
	"cerowrt-devel@lists.bufferbloat.net"
	<cerowrt-devel@lists.bufferbloat.net>,
	bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] [Codel] [Cerowrt-devel] FQ_Codel lwn draft article review
Date: Wed, 28 Nov 2012 10:51:03 -0800	[thread overview]
Message-ID: <1354128663.14302.488.camel@edumazet-glaptop> (raw)
In-Reply-To: <7700.1354127857@obiwan.sandelman.ca>

On Wed, 2012-11-28 at 13:37 -0500, Michael Richardson wrote:
> >>>>> "Paul" == Paul E McKenney <paulmck@linux.vnet.ibm.com> writes:
>     Paul> You lost me on this one.  It looks to me like
>     Paul> net/sched/sch_fq_codel.c 
>     Paul> in fact does hash packets into flows, so FQ-CoDel is
>     Paul> stochastic in the 
>     Paul> the same sense that SFQ is.  In particular, FQ-CoDel can hash a thin
>     Paul> session into the same flow as a thick session, which really is the
>     Paul> birthday effect.
> 
> Silly question from someone who should read more code, but...
> if one is hashing the packet to pick a flow bucket, shouldn't this hash
> occur before any application of address/port translation. ? (NAT)
> 
> (Maybe I've just found out that IPv6 + CoDel will be a killer
> combination)
> 

Why would it be a killer ?

A NATed flow becomes another flow, with its own hash

A tunnel might have a problem, _if_ the hash would be computed on
elements found on the outer header.

But luckily, we do a complete flow dissection.

(Assuming the default fq_codel classification)

 


  reply	other threads:[~2012-11-28 18:51 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAA93jw5yFvrOyXu2s2DY3oK_0v3OaNfnL+1zTteJodfxtAAzcQ@mail.gmail.com>
2012-11-23  8:57 ` [Bloat] " Dave Taht
2012-11-23 22:18   ` Paul E. McKenney
2012-11-24  0:07     ` Toke Høiland-Jørgensen
2012-11-24 16:19       ` Dave Taht
2012-11-24 16:36         ` [Bloat] [Cerowrt-devel] " dpreed
2012-11-24 19:57         ` [Bloat] [Codel] " Andrew McGregor
2012-11-26 21:13         ` Rick Jones
2012-11-26 21:19           ` Dave Taht
2012-11-26 22:16         ` [Bloat] " Toke Høiland-Jørgensen
2012-11-26 23:21           ` Toke Høiland-Jørgensen
2012-11-26 23:39             ` [Bloat] [Cerowrt-devel] " dpreed
2012-11-26 23:58               ` Toke Høiland-Jørgensen
2012-11-27 16:41                 ` Oliver Hohlfeld
2012-11-28  0:51                   ` Toke Høiland-Jørgensen
2012-11-28 19:21                     ` Greg White
2012-11-28 19:45                       ` Simon Barber
2012-11-28 20:01                         ` Oliver Hohlfeld
2012-11-28 21:40                         ` Greg White
2012-11-28 20:09                       ` Oliver Hohlfeld
2012-11-28 21:45                         ` Greg White
2012-11-26 17:20       ` [Bloat] " Paul E. McKenney
2012-11-26 21:05       ` [Bloat] [Codel] " Rick Jones
2012-11-26 23:18         ` Rick Jones
2012-11-27 22:03     ` [Bloat] [Cerowrt-devel] " Jim Gettys
2012-11-27 22:31       ` David Lang
2012-11-27 22:54         ` Paul E. McKenney
2012-11-27 23:15           ` [Bloat] [Codel] " Andrew McGregor
2012-11-28  0:51             ` Paul E. McKenney
2012-11-28 17:36             ` Paul E. McKenney
2012-11-28 14:06         ` [Bloat] " Michael Richardson
2012-11-27 22:49       ` Paul E. McKenney
2012-11-27 23:53         ` [Bloat] [Codel] " Greg White
2012-11-28  0:27           ` Paul E. McKenney
2012-11-28  3:43             ` Kathleen Nichols
2012-11-28  4:38               ` Paul E. McKenney
2012-11-28 16:01                 ` Paul E. McKenney
2012-11-28 16:16                   ` Jonathan Morton
2012-11-28 17:44                     ` Paul E. McKenney
2012-11-28 18:37                       ` Michael Richardson
2012-11-28 18:51                         ` Eric Dumazet [this message]
2012-11-28 21:44                           ` Michael Richardson
2012-11-28 19:00                       ` Eric Dumazet
     [not found]                         ` <87vcckb0el.fsf@toke.dk>
2012-12-02 21:47                           ` Andrew McGregor
2012-12-03  8:04                             ` Dave Taht
2012-12-02 22:07                           ` Eric Dumazet
     [not found]                             ` <87lidgaynn.fsf@toke.dk>
2012-12-02 22:30                               ` Eric Dumazet
2012-11-28 17:20       ` [Bloat] " Paul E. McKenney
     [not found]         ` <20121202230635.GA16359@linux.vnet.ibm.com>
     [not found]           ` <87obib5qf8.fsf@toke.dk>
2012-12-03 11:31             ` Dave Taht
     [not found]               ` <87fw3n5m9g.fsf@toke.dk>
2012-12-03 14:58                 ` Paul E. McKenney
2012-12-03 15:49                   ` [Bloat] [Codel] " Eric Dumazet
2012-12-03 15:03               ` [Bloat] " Paul E. McKenney
2012-12-03 15:58               ` David Woodhouse
2012-12-04  3:13                 ` [Bloat] [Codel] " Dan Siemon
2012-12-04  9:23                   ` Alex Burr
2012-12-05  3:41                     ` Dan Siemon
2012-12-05 20:33                       ` Alex Burr
2012-12-06  4:12                         ` Dan Siemon
2012-12-06 23:41                           ` Alex Burr
2012-12-05  0:01                   ` Sebastian Moeller
2012-11-30  1:09       ` [Bloat] " Dan Siemon
2013-01-01 20:50         ` Dan Siemon

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