KVM虚拟机CPU绑定性能调优
关于linux 进程的处理器亲和性的vCPU 隔离和绑定之前已经做过测试，查考 ubuntu中测试进程的处理器亲和性和vCPU的绑定
查考连接 Setting KVM processor affinities https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Virtualization/ch33s08.html
那么KVM 虚拟化下如何直接为虚拟机绑定CPU 呢，KVM 提供了很方便的方法
查看说有虚拟机
root@network:~# virsh list --all
Id Name State
----------------------------------------------------
2 instance-000000ef running
4 instance-000000f3 running
7 instance-00000120 running
10 instance-00000146 running
11 instance-00000147 running
12 instance-00000148 running
26 instance-00000157 running
35 instance-0000015c running
38 instance-00000158 running
39 instance-0000015b running
- instance-00000122 shut off查看虚拟机信息
root@network:~# virsh dumpxml instance-00000146
instance-00000146
45d77d2b-723f-40c8-a953-13f886a317f8
4194304
4194304
4
/machine
OpenStack Foundation
OpenStack Nova
2014.1.3
202b2f9b-3fb8-dc11-8e76-e03f490e5d2c
45d77d2b-723f-40c8-a953-13f886a317f8
root@network:~# ps -ef|grep instance-00000146
root 21561 13180 0 14:31 pts/12 00:00:00 grep --color=auto instance-00000146
libvirt+ 31858 1 5 Jan08 ? 17:09:02 /usr/bin/qemu-system-x86_64 -name instance-00000146 -S -machine pc-i440fx-trusty,accel=kvm,usb=off -cpu Opteron_G5,+bmi1,+perfctr_nb,+perfctr_core,+topoext,+nodeid_msr,+tce,+lwp,+wdt,+skinit,+ibs,+osvw,+cr8legacy,+extapic,+cmp_legacy,+fxsr_opt,+mmxext,+osxsave,+monitor,+ht,+vme -m 4096 -realtime mlock=off -smp 4,sockets=4,cores=1,threads=1 -uuid 45d77d2b-723f-40c8-a953-13f886a317f8 -smbios type=1,manufacturer=OpenStack Foundation,product=OpenStack Nova,version=2014.1.3,serial=202b2f9b-3fb8-dc11-8e76-e03f490e5d2c,uuid=45d77d2b-723f-40c8-a953-13f886a317f8 -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/instance-00000146.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=discard -no-hpet -no-shutdown -boot strict=on -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/var/lib/nova/instances/45d77d2b-723f-40c8-a953-13f886a317f8/disk,if=none,id=drive-virtio-disk0,format=qcow2,cache=none -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -drive file=/var/lib/nova/instances/45d77d2b-723f-40c8-a953-13f886a317f8/disk.swap,if=none,id=drive-virtio-disk1,format=qcow2,cache=none -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1 -netdev tap,fd=25,id=hostnet0,vhost=on,vhostfd=34 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=fa:16:3e:83:8e:cf,bus=pci.0,addr=0x3 -chardev file,id=charserial0,path=/var/lib/nova/instances/45d77d2b-723f-40c8-a953-13f886a317f8/console.log -device isa-serial,chardev=charserial0,id=serial0 -chardev pty,id=charserial1 -device isa-serial,chardev=charserial1,id=serial1 -device usb-tablet,id=input0 -vnc 0.0.0.0:8 -k en-us -device cirrus-vga,id=video0,bus=pci.0,addr=0x2 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6
root@network:~# ps -eLo ruser,pid,ppid,lwp,psr|grep 31858
libvirt+ 31858 1 31858 0
libvirt+ 31858 1 31867 6
libvirt+ 31858 1 31869 4
libvirt+ 31858 1 31871 7
libvirt+ 31858 1 31873 0
libvirt+ 31858 1 31882 7
libvirt+ 31858 1 19834 6
libvirt+ 31858 1 20272 6
libvirt+ 31858 1 20679 6
libvirt+ 31858 1 20925 6
libvirt+ 31858 1 20926 6
libvirt+ 31858 1 20927 6
libvirt+ 31858 1 20928 7
libvirt+ 31858 1 20930 6最后一列是cpu 的编号，重复执行 ps -eLo ruser,pid,ppid,lwp,psr|grep 31858 可以看到 线程是不停在不通cpu 上漂移的，绑定这么多线程是很麻烦的
利用 virsh vcpuinfo instance-00000146 查看每个vCPU 对应物理核心（也是浮动的）
root@network:~# virsh vcpuinfo instance-00000146
VCPU: 0
CPU: 4
State: running
CPU time: 16025.9s
CPU Affinity: yyyyyyyy 这里看到是宿主机所有物理CPU 核心，Y代表有可以使用，基于CPU时间片来回切换
VCPU: 1
CPU: 6
State: running
CPU time: 20221.3s
CPU Affinity: yyyyyyyy
VCPU: 2
CPU: 6
State: running
CPU time: 12179.5s
CPU Affinity: yyyyyyyy
VCPU: 3
CPU: 5
State: running
CPU time: 12411.4s
CPU Affinity: yyyyyyyy绑定instance-00000146 的vcpu0 到物理cpu3
root@network:~# virsh vcpupin instance-00000146 0 3
root@network:~# virsh vcpuinfo instance-00000146
VCPU: 0
CPU: 3
State: running
CPU time: 16033.7s
CPU Affinity: ---y---- 这里看到只有第三个cpu 为Y
VCPU: 1
CPU: 1
State: running
CPU time: 20234.7s
CPU Affinity: yyyyyyyy
VCPU: 2
CPU: 0
State: running
CPU time: 12188.5s
CPU Affinity: yyyyyyyy
VCPU: 3
CPU: 0
State: running
CPU time: 12420.2s
CPU Affinity: yyyyyyyyroot@network:~# virsh vcpupin instance-00000146 1 4
root@network:~# virsh vcpupin instance-00000146 2 5
root@network:~# virsh vcpupin instance-00000146 3 6
root@network:~# virsh vcpuinfo instance-00000146
VCPU: 0
CPU: 3
State: running
CPU time: 16050.3s
CPU Affinity: ---y----
VCPU: 1
CPU: 4
State: running
CPU time: 20255.6s
CPU Affinity: ----y---
VCPU: 2
CPU: 5
State: running
CPU time: 12203.2s
CPU Affinity: -----y--
VCPU: 3
CPU: 6
State: running
CPU time: 12438.0s
CPU Affinity: ------y-