Hi, Stefan：
I have done some testing to compare the performance of dataplane and
non-dataplane. But the result did not meet my expectations, the performance of
disk with dataplane enabled did not have advantage over non-dataplane.
The following contains the environment info and testing results.
Does my testing method or testing environment have something wrong ? Could you
give me some advice? I can provide more information if need.
1. Environment:
a). Qemu 1.4 master branch
b). kernel: 3.5.0-2.fc17.x86_64
c). virtual disks location: the same local SATA harddisk with ext4 fs
d). VM start cmd (os: win7/qed, disk1: raw/non-dataplane/10G/NTFS,
disk2: raw/dataplane/10G/NTFS) :
./x86_64-softmmu/qemu-system-x86_64 -enable-kvm -name win7 -M pc-0.15 -m 1024
-boot c -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -monitor
stdio -drive file=/home/win7.qed,if=none,format=qed,cache=none,id=drive0
-chardev spicevmc,id=charchannel2,name=vdagent -device
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel2,id=channel2,name=com.redhat.spice.0
-chardev pty,id=charchannel3 -device
virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel3,id=channel3,name=arbitrary.virtio.serial.port.name
-usb -device usb-tablet,id=input0 -spice port=3007,addr=****,disable-ticketing
-vga qxl -global qxl.vram_size=67108864 -device
AC97,id=sound0,bus=pci.0,addr=0x4 -device
virtio-blk-pci,drive=drive0,bus=pci.0,addr=0x6,bootindex=1 -drive
id=drive1,if=none,cache=none,format=raw,file=/home/data.img -device
virtio-blk-pci,drive=drive1,bus=pci.0,addr=0x7 -drive
id=drive2,if=none,cache=none,format=raw,file=/home/data2.img,aio=native -device
virtio-blk-pci,drive=drive2,bus=pci.0,addr=0x8,scsi=off,x-data-plane=on,config-wce=off
2. Testing Tool And Testing Params:
a). Only IOMeter App Running in VM, and no other IO in Host (Dom0)
b). 100% Random IO, data_size(16K/32K/4K), RW_Ratio(0%/25%/75% Read)
c). Testing of two disks separately, not simultaneously
3. Testing Results:
datasize/RW_Ratio IOPS_dataplane IOPS_non_dataplane
MBPS_dataplane MBPS_non_dataplane
16K/0% 294.094948 293.609606
4.595234 4.58765
16K/25% 283.096745 281.649258
4.423387 4.40077
16K/75% 316.039801 309.585336
4.938122 4.837271
32K/0% 257.529537 258.806128
8.047798 8.087692
32K/25% 253.729281 253.756673
7.92904 7.929896
32K/75% 292.384568 280.991434
9.137018 8.780982
4K/0% 321.599352 324.116063
1.256247 1.266078
4K/25% 309.906635 309.294278
1.210573 1.208181
4K/75% 350.168882 350.772329
1.367847 1.370204
----------
Leiqzhang
Best Regards
> 发件人: qemu-devel-bounces+zhangleiqiang=huawei....@nongnu.org
> [mailto:qemu-devel-bounces+zhangleiqiang=huawei....@nongnu.org] 代表 leiqzhang
> 发送时间: 2013年3月28日 12:03
> 收件人: Stefan Hajnoczi
> 抄送: pbonz...@redhat.com; qemu-devel@nongnu.org; stefa...@redhat.com; 张 磊强
> 主题: [Qemu-devel] 回复： dataplane bug: fail to start Windows VM with dataplane
> enable
>
> Hi, Stefan:
>
> Thank for your reply and patch. I have done the test for Windows 7,
> Windows 2003, and fedora.
>
> The patch has fixed the problem now, thanks.
>
> --
> leiqzhang
> Sent by Sparrow
>
> 在 2013年3月27日星期三，23:41，Stefan Hajnoczi 写道：
> On Tue, Mar 26, 2013 at 11:10:35PM +0800, 张磊强 wrote:
> Hi, Paolo && Stefan:
>
> When I test the dataplane feature with qemu master, I find that
> Windows (Windows 7 and Windows 2003) VM will hang if dataplane is
> enabled. But if I try to start a Fedora VM, it can start normally.
>
> The command I boot QEMU is:
> x86_64-softmmu/qemu-system-x86_64 -enable-kvm -m 1024 -smp 2 -drive
> file=win7.img,if=none,id=drive-virtio-disk,format=raw,cache=none,aio=native
> -device
> virtio-blk-pci,config-wce=off,scsi=off,x-data-plane=on,drive=drive-virtio-disk,id=virtio-disk
>
> I found the similar bug has reported some days ago:
> http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02200.html
> . And a patch for this bug has already committed by Paolo at Mar 13:
> http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02200.html
> .
>
> But it cannot work under my environment. Could you give me some advise
> to debug this problem ? I can provide more information if need.
>
> I sent a fix and CCed you on the patch. Please test it if you have
> time.
>
> Stefan
>
