[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [Bug 899140] Re: Problem with Linux Kernel Traffic Cont
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [Bug 899140] Re: Problem with Linux Kernel Traffic Control |
Date: |
Fri, 16 Dec 2011 08:31:03 +0000 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Dec 15, 2011 at 04:48:13PM -0000, Vincent Autefage wrote:
> Here is the problem !
>
> The Ubuntu version works only because it not uses an *Intel e1000* but a
> *rtl8139*.
> Therefore, the problem about the e1000 is present in *all* version
> (original or ubuntu ones).
>
> Thus, the file *e1000.c* must contain some instructions which imply the
> bad TC behavior.
You are right! Looking back at your QEMU command-line you are not
explicitly specifying the NIC model so the default will take effect.
Now we're back to square one: e1000.c performs poorly when the tc
command you posted is used. We don't know why yet.
Michael: Have you ever encountered unexpectedly low throughput when tc
is used inside the guest?
# tc qdisc add dev eth0 root tbf rate 20mbit burst 20k latency 50ms
The observed throughput from iperf is only 100kbit/s, not around
20mbit/s as expected. When tc is not run inside the guest then the NIC
saturates 20mbit/s easily.
Stefan
- [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