Shouta, Can it be reproduced if thp/hugetlbfs is disabled on both source and destination?
On 11/01/2012 08:12 AM, shouta.ueh...@jp.yokogawa.com wrote: > Hello. > > I have a problem with the performance of the guest Linux after live migration. > When I analyze the file I/O latency of the guest using LMbench3, the latency > of > the guest on the destination host is about 2 times bigger than the guest on > the > source host. As a result that I investigated it, this problem occurs if three > following conditions are right. > > 1. Use the kernel version 2.6.38.6-26.fc15.x86_64 or later. > 2. Execute system calls for low level file I/O (read, write, open etc.) on > the > guest. > 3. Enable EPT. > > Performance cannot decrease on other tests of LMbench3; numerical operation, > context switching, memory latencies etc. > > Is this an existing problem ? What should I do to resolve it ? > > --- > The situation the problem occurs > > CPU models : Intel Xeon E3-1245 (Both hosts have same cpu.) > Host kernel : 3.6.4 > Host OS : Fedora 16 64bit ver. (Both hosts have same OS.) > Guest OS : Fedora 16 64bit ver., kernel 3.1.0-7.fc16.x86_64 > QEMU version : qemu-kvm 1.2.0 > QEMU parameter : qemu-kvm -m 1024 -drive file=guest.qcow2,if=virtio \ > -boot order=c,menu=on -k ja > (-incoming tcp:192.168.0.51:4444 set only destination) > QEMU command : migrate -d tcp:192.168.0.51:4444 > Analyses : LMbench version 3 > > [Guest on the source host] > $ ./lat_syscall open > Simple open/close: 1.4281 microseconds > $ ./lat_syscall read > Simple read: 0.1416 microseconds > $ ./lat_syscall write > Simple write: 0.1194 microseconds > $ ./lat_fs -s 0 > 0k 550 98726 247712 > 1k 383 69751 193985 > 4k 381 69348 193383 > 10k 313 54369 155697 > > [Guest on the source host] > $ ./lat_syscall open > Simple open/close: 1.6126 microseconds > $ ./lat_syscall read > Simple read: 0.2206 microseconds > $ ./lat_syscall write > Simple write: 0.1980 microseconds > $ ./lat_fs -s 0 > 0k 427 83252 243222 > 1k 315 60530 191650 > 4k 184 34535 190947 > 10k 65 11922 152608 > --- > > Thanks. > > Shota Uehara <Shouta.Uehara()jp.yokogawa.com> > > > ----- > CONFIDENTIAL: This e-mail may contain information that is confidential or > otherwise protected from disclosure and intended only for the party to whom > it is addressed. If you are not the intended recipient, please notify the > sender by return and delete this e-mail. You are hereby formally advised that > any unauthorized use, disclosure or copying of this email is strictly > prohibited and may be unlawful. > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
