From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Fri, 06 May 2005 00:19:15 +0000 Subject: Re: [LARTC] HTB rate miscalculation Message-Id: <427AB803.6080000@dsl.pipex.com> List-Id: References: <029901c550fc$77524c30$1f00a8c0@Micro1> In-Reply-To: <029901c550fc$77524c30$1f00a8c0@Micro1> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Marcus Felipe Pereira wrote: > Hi, > I've migrated my tc configuration from CBQ to HTB. > > One problem appeared. Htb seems to miscalculate the bandwidth for > classes with greater rates. > For rates below 2Mbit there is almost no difference between the > configured and the measured rate. > > For large ones the problem starts. My root class has 10Mbit rate and > when the interface has heavy trafic the measured bandwidth coudn't get > more then 8.5Mbit. > > "# tc -s class show ...." shows that the root class has about the > 10Mbit, but the link stats shows mutch less. > > The solution was to put the htb ceil on about 12Mbit. Then I can get to > the 10Mbit. When using CBQ I didn't have this problem. > > Is there any parameter that I can change to correct the rate calculation? > Any one has similar problem? What counters are you using to measure? Does it do the same if you test with a single tcp stream and a very simple setup like - tc qdisc add dev eth0 root handle 1:0 htb tc class add dev eth0 parent 1:0 classid 1:1 htb rate 10mbit tc filter add dev eth0 parent 1:0 protocol ip u32 match u32 0 0 flowid 1:1 Andy. _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc