> -----邮件原件----- > 发件人: Anthony Liguori [mailto:anth...@codemonkey.ws] > 发送时间: 2013年4月7日 22:06 > 收件人: Zhangleiqiang; Stefan Hajnoczi; stefa...@redhat.com > 抄送: Zhangleiqiang; Luohao (brian); qemu-devel@nongnu.org; Haofeng; > leiqzhang > 主题: Re: [Qemu-devel] question about performance of dataplane > > Zhangleiqiang <zhangleiqi...@huawei.com> writes: > > > > > 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 > > I doubt you'll see any performance difference with a single SATA drive. > There's no real parallelism possible as you have exactly one spindle > available. >
> > 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 > > > You are getting 300 MB/s to a single SATA disk? I strongly suspect > you are seeing cache interaction. I'd suggest disabling WCE on the disk > if you're going to benchmark like this. > > I'd also guess 300 MB/s is what you're maxing out at with native too. > So presumably normal virtio-blk is already getting close to native > performance. dataplane certainly isn't going to give you better than > native performance :-) > Maybe the result table in mail is not so clear, the IOPS is about 300, but the throughput is just about 1-9 MB/s, :) > Regards, > > Anthony Liguori > > > > > > > > > ---------- > > 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 > >>