[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [Bug 1036363] Re: Major network performance problems on AMD
From: |
Ziemowit Pierzycki |
Subject: |
[Qemu-devel] [Bug 1036363] Re: Major network performance problems on AMD hardware |
Date: |
Tue, 21 Aug 2012 19:55:41 -0000 |
** Also affects: qemu-kvm
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1036363
Title:
Major network performance problems on AMD hardware
Status in QEMU:
New
Status in qemu-kvm:
New
Bug description:
Hi,
I am experiencing some major performance problems with all of our
beefy AMD Opteron 6274 servers running Fedora 17 (kernel
3.4.4-5.fc17.x86_64, qemu 1.0-17). The network performance between
host and the virtual machine is terrible:
# iperf -c 10.10.11.22 -r
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 10.10.11.22, TCP port 5001
TCP window size: 197 KByte (default)
------------------------------------------------------------
[ 5] local 10.10.11.199 port 44192 connected with 10.10.11.22 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-10.0 sec 2.45 GBytes 2.11 Gbits/sec
[ 4] local 10.10.11.199 port 5001 connected with 10.10.11.22 port 42601
[ 4] 0.0-10.0 sec 8.97 GBytes 7.71 Gbits/sec
So the VM's receive is super slow. I would be happy with 7.71 Gbps
because it's closer to matching the speed of the 10G ethernet adapters
but the iSCSI drive's write performance is few times faster than read.
Now running a similar test on the slowest machine I have, Intel core
i3 I see this:
# iperf -c 192.168.7.60 -r
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.7.60, TCP port 5001
TCP window size: 306 KByte (default)
------------------------------------------------------------
[ 5] local 192.168.7.98 port 53992 connected with 192.168.7.60 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-10.0 sec 22.5 GBytes 19.3 Gbits/sec
[ 4] local 192.168.7.98 port 5001 connected with 192.168.7.60 port 53339
[ 4] 0.0-10.0 sec 25.1 GBytes 21.5 Gbits/sec
As you can image this is a huge difference in network IO. Most setups
are identical down to the same versions. Vhost-net is enabled and it
appears to use MSI-X on the VM. I've tried all kinds of settings and
while they improve performance a little I feel it's just masking a
bigger problem. All 12 of my AMD servers have this issue and it
appears I'm not the only one complaining. Any help would be
appreciated. Thanks.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1036363/+subscriptions
- [Qemu-devel] [RFC-v3 0/5] vhost-scsi: Add support for host virtualized target, Nicholas A. Bellinger, 2012/08/21
- [Qemu-devel] [RFC-v3 1/5] monitor: Rename+move net_handle_fd_param -> monitor_handle_fd_param, Nicholas A. Bellinger, 2012/08/21
- [Qemu-devel] [RFC-v3 3/5] vhost-scsi: add -vhost-scsi host device for use with tcm-vhost, Nicholas A. Bellinger, 2012/08/21
- [Qemu-devel] [RFC-v3 2/5] vhost: Pass device path to vhost_dev_init(), Nicholas A. Bellinger, 2012/08/21
- [Qemu-devel] [RFC-v3 5/5] virtio-scsi: Set max_target=0 during vhost-scsi operation, Nicholas A. Bellinger, 2012/08/21
- [Qemu-devel] [RFC-v3 4/5] virtio-scsi: Add start/stop functionality for vhost-scsi, Nicholas A. Bellinger, 2012/08/21