[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [Bug 899140] Re: Problem with Linux Kernel Traffic Cont
Re: [Qemu-devel] [Bug 899140] Re: Problem with Linux Kernel Traffic Control
Wed, 14 Dec 2011 14:42:12 -0000
Ok so the *Intel e1000* seems the only card which is impacted by the
Le 05/12/2011 12:11, Stefan Hajnoczi a écrit :
> On Mon, Dec 5, 2011 at 10:45 AM, Vincent Autefage
> <address@hidden> wrote:
>> So we have another problem...
>> The thing is that the 0.14.0 (and all 0.14.0 rc) built from GIT has the
>> same problem.
>> However, the package 0.14.0 from Ubuntu does not has this bug...
> Okay, that's actually a good thing because the issue is now isolated
> to two similar builds: 0.14.0 from source and 0.14.0 from Ubuntu.
> Either there is an environmental difference in the build configuration
> or Ubuntu has applied patches on top of vanilla 0.14.0.
> I think the next step is to grab the Ubuntu 0.14.0 source package and
> rebuild it to confirm that it does *not* have the bug.
> Then it's just a matter of figuring out what the difference is by a
> (manual) bisection.
> Are you using qemu-kvm? I found Ubuntu's 0.14.0-based package here:
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
Problem with Linux Kernel Traffic Control
Status in QEMU:
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
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.
To manage notifications about this bug go to:
- [Qemu-devel] [PATCH v2 0/9] various ARM fixes, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH v2 4/9] arm: add dummy gic security registers, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH v2 2/9] arm: Set frequencies for arm_timer, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH 5/9] ahci: convert ahci_reset to use AHCIState, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH v2 1/9] arm: add missing scu registers, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH 9/9] arm: increase a9mp interrupts to 160, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH v2 3/9] arm: add dummy v7 cp15 config_base_register, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH v2 8/9] Add xgmac ethernet model, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH 6/9] ahci: add support for non-PCI based controllers, Mark Langsdorf, 2011/12/22
- [Qemu-devel] [PATCH v2 7/9] add L2x0/PL310 cache controller device, Mark Langsdorf, 2011/12/22