From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dan Farino" Date: Wed, 13 Nov 2002 07:02:04 +0000 Subject: RE: [LARTC] Extremely inaccurate results using either TBF or HTB MIME-Version: 1 Content-Type: multipart/mixed; boundary="----_=_NextPart_001_01C28AE2.92800E95" Message-Id: List-Id: References: In-Reply-To: To: lartc@vger.kernel.org This is a multi-part message in MIME format. ------_=_NextPart_001_01C28AE2.92800E95 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Jannes, =20 That worked great! Everything is dead-on accurate now.=20 =20 Thank you very much for your help! =20 Dan Farino Sr. System Engineer Stamps.com, Inc. Santa Monica, CA =20 -----Original Message----- From: sufcrusher [mailto:sufcrusher@zonnet.nl]=20 Sent: Tuesday, November 12, 2002 3:11 PM To: Dan Farino; lartc@mailman.ds9a.nl Subject: Re: [LARTC] Extremely inaccurate results using either TBF or HTB =20 This worked miracles for me: =20 change /usr/src/linux/include/net/pkt_sched.h PSCHED_CLOCK_SOURCE to PSCHED_CPU if you have a cpu with timestamp counter (TSC) that will give you Mhz timer granularity. =20 (don't forget to recompile of course) =20 Jannes Faber ----- Original Message -----=20 From: Dan Farino =20 To: lartc@mailman.ds9a.nl=20 Sent: Tuesday, November 12, 2002 9:57 AM Subject: [LARTC] Extremely inaccurate results using either TBF or HTB =20 Hi everyone, =20 I am getting extremely inaccurate results from my setup: - RedHat 8.0 on a Compaq ProLiant 1600, dual PII/450, Intel Dual 100 NIC - I've tried both SMP and non-SMP kernels. - I'm using the updated tc from the HTB home page. - I'm using the HTB that comes with the RH8 kernel. =20 Here's what's happening. If I, for instance: tc qdisc add dev eth2 root tbf rate 1.9mbit buffer 20Kb/8 limit 15Kb =20 Then my download rate goes at 360,000 bytes/s, which, by my calculations, is 2.77mbit. I am using Win2k perfmon to test the speed. The line is flat and the speed is very consistent (consistently *wrong*, unfortunately...) =20 Immediately after, I do: tc qdisc change dev eth2 root tbf rate 1.8mbit buffer 20Kb/8 limit 15Kb =20 My download speed is then 243,000 bytes/s, or 1.85mbit. Again, very flat, consistent line. =20 I have played with the parameters on both TBF and HTB in many different configurations. I always seem to have a large jump between 1.8-1.9. I can't find any number between those two that will actually produce a 2mbit limit. I know 1.85 is close to 2.0, but is this the expected margin of error? (Then again, 2.77 isn't close to 1.9 at all, so I hope not!) =20 Has anyone else experienced anything like this? =20 Thank you very much for any help you can provide! =20 Dan Farino Sr. System Engineer Stamps.com, Inc. Santa Monica, CA =20 ------_=_NextPart_001_01C28AE2.92800E95 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Jannes,

That worked great! Everything is = dead-on accurate now.

Thank you very much for your = help!

Dan = Farino

Sr. System = Engineer

Stamps.com, = Inc.

Santa = Monica, CA

-----Original = Message-----
From: sufcrusher [mailto:sufcrusher@zonnet.nl]
Sent: Tuesday, November = 12, 2002 3:11 PM
To: Dan Farino; lartc@mailman.ds9a.nl
Subject: Re: [LARTC] = Extremely inaccurate results using either TBF or HTB

This worked miracles for = me:

change /usr/src/linux/include/net/pkt_sched.h
PSCHED_CLOCK_SOURCE to PSCHED_CPU if you have a cpu with timestamp
counter (TSC) that will give you Mhz timer = granularity.

(don't forget to recompile = of course)

Jannes = Faber

----- Original Message = -----

From: Dan = Farino

To:<= /font> lartc@mailman.ds9a.nl

Sent: Tuesday, November 12, 2002 9:57 AM

Subject: [LARTC] Extremely inaccurate results using either TBF or HTB

Hi = everyone,

I am getting extremely = inaccurate results from my setup:

- RedHat 8.0 on a Compaq = ProLiant 1600, dual PII/450, Intel Dual 100 NIC

- I’ve tried both = SMP and non-SMP kernels.

- I’m using the = updated tc from the HTB home page.

- I’m using the HTB = that comes with the RH8 kernel.

Here’s what’s happening. If I, for instance:

= tc qdisc add dev eth2 root tbf rate 1.9mbit buffer 20Kb/8 limit = 15Kb

Then my download rate = goes at 360,000 bytes/s, which, by my calculations, is 2.77mbit. I am using Win2k = perfmon to test the speed. The line is flat and the speed is very consistent = (consistently *wrong*, = unfortunately…)

Immediately after, I = do:

= tc qdisc change dev eth2 root tbf rate 1.8mbit buffer 20Kb/8 limit = 15Kb

My download speed is then = 243,000 bytes/s, or 1.85mbit. Again, very flat, consistent = line.

I have played with the = parameters on both TBF and HTB in many different configurations. I always seem to = have a large jump between 1.8-1.9. I can’t find any number between those = two that will actually produce a 2mbit limit. I know 1.85 is close to 2.0, = but is this the expected margin of error? (Then again, 2.77 isn’t close = to 1.9 at all, so I hope not!)

Has anyone else = experienced anything like this?

Thank you very much for = any help you can provide!

Dan Farino

Sr. System Engineer

Stamps.com, Inc.

Santa Monica, CA

=00 ------_=_NextPart_001_01C28AE2.92800E95-- _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/