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From: Rick Jones <rick.jones2@hp.com>
To: "John W. Linville" <linville@tuxdriver.com>
Cc: bloat@lists.bufferbloat.net
Subject: Re: [Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps?
Date: Tue, 15 Mar 2011 18:02:47 -0700	[thread overview]
Message-ID: <1300237367.2087.2238.camel@tardy> (raw)
In-Reply-To: <20110316003234.GC28663@tuxdriver.com>

On Tue, 2011-03-15 at 20:32 -0400, John W. Linville wrote:
> On Tue, Mar 15, 2011 at 02:31:59PM -0700, Rick Jones wrote:
> > On Tue, 2011-03-15 at 16:51 -0400, John W. Linville wrote:
> > > On Tue, Mar 15, 2011 at 09:40:06PM +0200, Jonathan Morton wrote:
> > > > 
> > > > On 15 Mar, 2011, at 8:31 pm, John W. Linville wrote:
> > > > 
> > > > > If you don't throttle _both_
> > > > > the _enqueue_ and the _dequeue_, then you could be keeping a nice,
> > > > > near-empty tx queue on the host and still have a long, bloated queue
> > > > > building at the device.
> > > > 
> > > > Don't devices at least let you query how full their queue is?
> > > 
> > > I suppose it depends on what you mean?  Presumably drivers know that,
> > > or at least can figure it out.  The accuracy of that might depend on
> > > the exact mechanism, how often the tx rings are replinished, etc.
> > > 
> > > However, I'm not aware of any API that would let something in the
> > > stack (e.g. a qdisc) query the device driver for the current device
> > > queue depth.  At least, I don't think Linux has one -- do other
> > > kernels/stacks provide that?
> > 
> > HP-UX's lanadmin (and I presume the nwmgr command in 11.31) command will
> > display the "classic" interface MIB stats, which includes the outbound
> > queue length.  What it does (or should do) for that statistic in the
> > face of a multi-queue device I've no idea :)
> 
> But that is capacity, right?  Not current occupancy?  I thought that
> was the outcome of an earlier thread?

No, HP-UX shows current occupancy on its interfaces.   I think it is
Cisco which shows capacity - at least that is my recollection of one of
the other discussions.

rick


  reply	other threads:[~2011-03-16  1:02 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-15 10:36 Jim Gettys
2011-03-15 14:40 ` Jim Gettys
2011-03-15 16:47   ` Jonathan Morton
2011-03-15 17:59     ` Don Marti
2011-03-15 18:14       ` Rick Jones
2011-03-15 18:31         ` John W. Linville
2011-03-15 19:40           ` Jonathan Morton
2011-03-15 19:59             ` Rick Jones
2011-03-15 20:51             ` John W. Linville
2011-03-15 21:31               ` Rick Jones
2011-03-16  0:32                 ` John W. Linville
2011-03-16  1:02                   ` Rick Jones [this message]
2011-03-15 22:01               ` Jonathan Morton
2011-03-15 22:19                 ` Stephen Hemminger
2011-03-15 22:26                   ` Jonathan Morton
2011-03-15 22:36                     ` Rick Jones
2011-03-15 22:40                       ` Jonathan Morton
2011-03-15 22:42                         ` Stephen Hemminger
2011-03-15 22:52                       ` Eric Dumazet
2011-03-15 23:02                         ` Rick Jones
2011-03-15 23:12                         ` Jonathan Morton
2011-03-15 23:25                           ` Rick Jones
2011-03-15 23:33                             ` Jonathan Morton
2011-03-15 23:46                         ` Dave Täht
2011-03-16  0:49                           ` Jonathan Morton
2011-03-16  1:02                             ` Dave Täht
2011-03-16  1:28                               ` Jonathan Morton
2011-03-16  1:59                                 ` Dave Täht
2011-03-16  2:23                                   ` Jonathan Morton
2011-03-16 22:22                                     ` [Bloat] Random idea in reaction to all the discussion of TCPflavours " Richard Scheffenegger
2011-03-16 23:38                                       ` richard
2011-03-16 23:50                                         ` Rick Jones
2011-03-17 12:05                                       ` Fred Baker
2011-03-17 12:18                                         ` Fred Baker
2011-03-17 17:27                                           ` Dave Täht
2011-03-18 18:30                                           ` Richard Scheffenegger
2011-03-18 18:49                                             ` Fred Baker
2011-03-20 11:40                                               ` Jonathan Morton
2011-03-20 22:18                                                 ` david
2011-03-20 22:45                                                   ` Jonathan Morton
2011-03-20 22:50                                                     ` Dave Täht
2011-03-20 22:55                                                       ` grenville armitage
2011-03-20 23:04                                                         ` Dave Täht
2011-03-20 23:14                                                           ` Jonathan Morton
2011-03-20 23:19                                                             ` Dave Täht
2011-03-20 23:23                                                               ` Dave Täht
2011-03-20 22:58                                                       ` Jonathan Morton
2011-03-21  1:28                                                     ` david
2011-03-21  1:56                                                       ` Wesley Eddy
2011-03-18 18:27                                       ` [Bloat] Random idea in reaction to all the discussion ofTCPflavours " Richard Scheffenegger
2011-03-16 22:07                           ` [Bloat] Random idea in reaction to all the discussion of TCPflavours " Richard Scheffenegger
2011-03-17  0:10                             ` Jonathan Morton
2011-03-16  0:47                 ` [Bloat] Random idea in reaction to all the discussion of TCP flavours " John W. Linville
2011-03-16 20:07                   ` Jim Gettys
2011-03-17  2:26                     ` Jonathan Morton
2011-03-17 18:22                       ` Rick Jones
2011-03-17 21:50                         ` Jonathan Morton
2011-03-17 22:20                           ` Rick Jones
2011-03-17 22:56                             ` Jonathan Morton
2011-03-18  1:36                               ` Justin McCann
2011-03-18  5:51                             ` Eric Dumazet
2011-03-15 16:34 ` Jonathan Morton
2011-03-15 18:13   ` Stephen Hemminger
2011-03-16  5:41 ` Fred Baker
2011-03-16  6:26   ` Jonathan Morton
2011-03-16  8:55 ` [Bloat] Random idea in reaction to all the discussion of TCPflavours " Richard Scheffenegger
2011-03-16  9:04 ` [Bloat] Random idea in reaction to all the discussion of TCP flavours " BeckW
2011-03-16 22:48   ` Fred Baker
2011-03-16 23:23     ` Jonathan Morton
2011-03-17  8:34     ` BeckW

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