The result without TC is about 120 Mbit/s. I check the bandwidth with lot of programs (not only with Iperf) and the result is also the same....
However, if I use the same raw image and the same TC configuration with the version 0.14.0 of QEMU or with some real physical hosts, the result with TC is about 19.2 Mbit/s what is the desired result... Vincent Le 03/12/2011 19:48, Stefan Hajnoczi a écrit : > On Fri, Dec 2, 2011 at 2:42 PM, Vincent Autefage > <899...@bugs.launchpad.net> wrote: >> *root@A# tc qdisc add dev eth0 root tbf rate 20mbit burst 20480 latency >> 50ms* >> >> *root@B# **ifconfig eth0 192.168.0.2* >> >> Then if we check with /Iperf/, the real rate will be about 100kbit/s : > What is the iperf result without tc? It's worth checking what rate > the unlimited interface saturates at before applying tc. Perhaps this > setup is just performing very poorly and it has nothing to do with tc. > > Stefan > -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/899140 Title: Problem with Linux Kernel Traffic Control Status in QEMU: New Bug description: Hi, The last main versions of QEMU (0.14.1, 0.15 and 1.0) have an important problem when running on a Linux distribution which running itself a Traffic Control (TC) instance. Indeed, when TC is configured with a Token Bucket Filter (TBF) with a particular rate, the effective rate is very slower than the desired one. For instance, lets consider the following configuration : # tc qdisc add dev eth0 root tbf rate 20mbit burst 20k latency 50ms The effective rate will be about 100kbit/s ! (verified with iperf) I've encountered this problem on versions 0.14.1, 0.15 and 1.0 but not with the 0.14.0... In the 0.14.0, we have a rate of 19.2 mbit/s which is quiet normal. I've done the experimentation on several hosts : - Debian 32bit core i7, 4GB RAM - Debian 64bit core i7, 8GB RAM - 3 different high performance servers : Ubuntu 64 bits, 48 AMD Opteron, 128GB of RAM The problem is always the same... The problem is also seen with a Class Based Queuing (CBQ) in TC. Thanks To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/899140/+subscriptions
