這篇文章主要介紹了對KVM虛擬機進行cpu pinning配置的方法,通過文中的各種virsh命令可進行操作,需要的朋友可以參考下 首先需求了解基本的信息

1 宿主機CPU特性查看

使用virsh nodeinfo可以看到一些基本信息

#virsh nodeinfo CPU model: x86_64 CPU(s): 32 CPU frequency: 1200 MHz CPU socket(s): 1 Core(s) per socket: 8 Thread(s) per core: 2 NUMA cell(s): 2 Memory size: 132119080 KiB

使用virsh capabilities可以查看物理機CPU的詳細信息，包括物理CPU個數，每個CPU的核數，是否開了超線程。

#virsh capabilities <capabilities><host><uuid>36353332-3030-3643-5534-3235445a564a</uuid><cpu><arch>x86_64</arch><model>SandyBridge</model><vendor>Intel</vendor><topology sockets='1' cores='8' threads='2'/><feature name='erms'/><feature name='smep'/>...</cpu><power_management><suspend_disk/></power_management><migration_features><live/><uri_transports><uri_transport>tcp</uri_transport></uri_transports></migration_features><topology><cells num='2'><cell id='0'><cpus num='16'><cpu id='0' socket_id='0' core_id='0' siblings='0,16'/>...<cpu id='23' socket_id='0' core_id='7' siblings='7,23'/></cpus></cell><cell id='1'><cpus num='16'><cpu id='8' socket_id='1' core_id='0' siblings='8,24'/>...<cpu id='31' socket_id='1' core_id='7' siblings='15,31'/></cpus></cell></cells></topology><secmodel><model>none</model><doi>0</doi></secmodel><secmodel><model>dac</model><doi>0</doi></secmodel></host> ... </capabilities>

使用virsh freecell命令查看可以當前空閑內存

#virsh freecell --all0: 787288 KiB1: 94192 KiB -------------------- Total: 881480 KiB

物理CPU的特性也可以通過/proc/cpuinfo查看

#cat /proc/cpuinfo rocessor : 0 vendor_id : GenuineIntel cpu family : 6 model : 62 model name : Intel(R) Xeon(R) CPU E5-2640 v2 @ 2.00GHz stepping : 4 cpu MHz : 1200.000 cache size : 20480 KB physical id : 0 siblings : 16 core id : 0 cpu cores : 8 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm ida arat epb xsaveopt pln pts dts tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms bogomips : 3990.67 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: ...

綜合上面的信息，我們可以得出以下信息：

1) 物理CPU為 E5-2640V2，為8核2顆，開啟了超線程，在物理機系統上可以看到32個CPU；

2) 物理機內存為128G?

2 虛擬機CPU使用情況查看

可以使用virsh vcpuinfo命令查看虛擬機vcpu和物理CPU的對應關系

#virsh vcpuinfo 21 VCPU: 0 CPU: 25 State: running CPU time: 10393.0s CPU Affinity: --------yyyyyyyy--------yyyyyyyy VCPU: 1 CPU: 8 State: running CPU time: 7221.2s CPU Affinity: --------yyyyyyyy--------yyyyyyyy ...

可以看到vcpu0被調度到物理機CPU25上，目前是使用狀態，使用時間是10393.0s

CPU Affinity: --------yyyyyyyy--------yyyyyyyy

yyyyyyy表示可以使用的物理CPU內部的邏輯核，可以看到這臺虛擬機可以在8-15， 24-31這些cpu之間調度，為什么不能使用0-7，16-23這些CPU呢，是因為系統的自動numa平衡服務在發生作用，一個虛擬機默認只能使用同一顆物理CPU內部的邏輯核。

使用emulatorpin可以查看虛擬機可以使用那些物理邏輯CPU

#virsh emulatorpin 21 emulator: CPU Affinity ----------------------------------*: 0-31

可以看到0-31我們都可以使用，意味這我們也可以強制將CPU調度到任何CPU上。

3 在線pinning虛擬機的cpu

強制讓虛擬機只能在26-31這些cpu之間調度

#virsh emulatorpin 21 26-31 --live

查看結果

#virsh emulatorpin 21 emulator: CPU Affinity ----------------------------------*: 26-31

查看vcpu info

#virsh vcpuinfo 21 VCPU: 0 CPU: 28 State: running CPU time: 10510.5s CPU Affinity: --------------------------yyyyyy VCPU: 1 CPU: 28 State: running CPU time: 7289.7s CPU Affinity: --------------------------yyyyyy ...</p> <p>

查看xml文件

#virsh dumpxml 21 <domain type='kvm' id='21'><name>cacti-230</name><uuid>23a6455c-5cd1-20cd-ecfe-2ba89be72c41</uuid><memory unit='KiB'>4194304</memory><currentMemory unit='KiB'>4194304</currentMemory><vcpu placement='static'>4</vcpu><cputune><emulatorpin cpuset='26-31'/></cputune>

我們也可以強制vcpu和物理機cpu一對一的綁定

強制vcpu 0和物理機cpu 28綁定

強制vcpu 1和物理機cpu 29綁定

強制vcpu 2和物理機cpu 30綁定

強制vcpu 3和物理機cpu 31綁定

#virsh vcpupin 21 0 28 #virsh vcpupin 21 1 29 #virsh vcpupin 21 2 30 #virsh vcpupin 21 3 31

查看xml文件，生效了

#virsh dumpxml 21 <domain type='kvm' id='21'><name>cacti-230</name><uuid>23a6455c-5cd1-20cd-ecfe-2ba89be72c41</uuid><memory unit='KiB'>4194304</memory><currentMemory unit='KiB'>4194304</currentMemory><vcpu placement='static'>4</vcpu><cputune><vcpupin vcpu='0' cpuset='28'/><vcpupin vcpu='1' cpuset='29'/><vcpupin vcpu='2' cpuset='30'/><vcpupin vcpu='3' cpuset='31'/><emulatorpin cpuset='26-31'/></cputune>

是vcpuino命令查看，可以看到配置生效了

#virsh vcpuinfo 22 VCPU: 0 CPU: 28 State: running CPU time: 1.8s CPU Affinity: ----------------------------y--- VCPU: 1 CPU: 29 State: running CPU time: 0.0s CPU Affinity: -----------------------------y-- ...

?

4 cpu pinning簡單的性能測試

cpu pinning到底對cpu的性能影響有多大，進行了一個簡單的測試。

測試環境

硬件：ntel(R) Xeon(R) CPU X5650 @ 2.67GHz 2顆

軟件：centos 7 update到內核 3.10.0-123.8.1.el7.x86_64

虛擬機：centos 7 update到內核 3.10.0-123.8.1.el7.x86_64

虛擬機cpu：1顆

測試工具：unixbench 5.1.2

?

不做cpu綁定測試結果

1 CPU in system; running 1 parallel copy of tests
Dhrystone 2 using register variables?????? 28890881.0 lps?? (10.0 s, 7 samples)
Double-Precision Whetstone???????????????????? 3880.4 MWIPS (9.0 s, 7 samples)
Execl Throughput?????????????????????????????? 4146.3 lps?? (30.0 s, 2 samples)
File Copy 1024 bufsize 2000 maxblocks?????? 1051084.3 KBps? (30.0 s, 2 samples)
File Copy 256 bufsize 500 maxblocks????????? 286552.2 KBps? (30.0 s, 2 samples)
File Copy 4096 bufsize 8000 maxblocks?????? 2142638.4 KBps? (30.0 s, 2 samples)
Pipe Throughput???????????????????????????? 1726807.0 lps?? (10.0 s, 7 samples)
Pipe-based Context Switching???????????????? 322865.5 lps?? (10.0 s, 7 samples)
Process Creation????????????????????????????? 13662.4 lps?? (30.0 s, 2 samples)
Shell Scripts (1 concurrent)?????????????????? 5955.4 lpm?? (60.0 s, 2 samples)
Shell Scripts (8 concurrent)??????????????????? 713.1 lpm?? (60.0 s, 2 samples)
System Call Overhead??????????????????????? 2138318.1 lps?? (10.0 s, 7 samples)
System Benchmarks Index Values?????????????? BASELINE?????? RESULT??? INDEX
Dhrystone 2 using register variables???????? 116700.0?? 28890881.0?? 2475.7
Double-Precision Whetstone?????????????????????? 55.0?????? 3880.4??? 705.5
Execl Throughput???????????????????????????????? 43.0?????? 4146.3??? 964.2
File Copy 1024 bufsize 2000 maxblocks????????? 3960.0??? 1051084.3?? 2654.3
File Copy 256 bufsize 500 maxblocks??????????? 1655.0???? 286552.2?? 1731.4
File Copy 4096 bufsize 8000 maxblocks????????? 5800.0??? 2142638.4?? 3694.2
Pipe Throughput?????????????????????????????? 12440.0??? 1726807.0?? 1388.1
Pipe-based Context Switching?????????????????? 4000.0???? 322865.5??? 807.2
Process Creation??????????????????????????????? 126.0????? 13662.4?? 1084.3
Shell Scripts (1 concurrent)???????????????????? 42.4?????? 5955.4?? 1404.6
Shell Scripts (8 concurrent)????????????????????? 6.0??????? 713.1?? 1188.4
System Call Overhead????????????????????????? 15000.0??? 2138318.1?? 1425.5
?????????????????????????????????????????????????????????????????? ========
System Benchmarks Index Score??????????????????????????????????????? 1444.7

做了cpu綁定測試結果

1 CPU in system; running 1 parallel copy of tests
Dhrystone 2 using register variables?????? 29812559.6 lps?? (10.0 s, 7 samples)
Double-Precision Whetstone???????????????????? 3928.7 MWIPS (8.9 s, 7 samples)
Execl Throughput?????????????????????????????? 4314.4 lps?? (30.0 s, 2 samples)
File Copy 1024 bufsize 2000 maxblocks?????? 1068627.9 KBps? (30.0 s, 2 samples)
File Copy 256 bufsize 500 maxblocks????????? 291834.2 KBps? (30.0 s, 2 samples)
File Copy 4096 bufsize 8000 maxblocks?????? 2052612.8 KBps? (30.0 s, 2 samples)
Pipe Throughput???????????????????????????? 1737466.2 lps?? (10.0 s, 7 samples)
Pipe-based Context Switching???????????????? 326839.9 lps?? (10.0 s, 7 samples)
Process Creation????????????????????????????? 14234.5 lps?? (30.0 s, 2 samples)
Shell Scripts (1 concurrent)?????????????????? 6040.8 lpm?? (60.0 s, 2 samples)
Shell Scripts (8 concurrent)??????????????????? 717.4 lpm?? (60.1 s, 2 samples)
System Call Overhead??????????????????????? 2149194.4 lps?? (10.0 s, 7 samples)
System Benchmarks Index Values?????????????? BASELINE?????? RESULT??? INDEX
Dhrystone 2 using register variables???????? 116700.0?? 29812559.6?? 2554.6
Double-Precision Whetstone?????????????????????? 55.0?????? 3928.7??? 714.3
Execl Throughput???????????????????????????????? 43.0?????? 4314.4?? 1003.4
File Copy 1024 bufsize 2000 maxblocks????????? 3960.0??? 1068627.9?? 2698.6
File Copy 256 bufsize 500 maxblocks??????????? 1655.0???? 291834.2?? 1763.3
File Copy 4096 bufsize 8000 maxblocks????????? 5800.0??? 2052612.8?? 3539.0
Pipe Throughput?????????????????????????????? 12440.0??? 1737466.2?? 1396.7
Pipe-based Context Switching?????????????????? 4000.0???? 326839.9??? 817.1
Process Creation??????????????????????????????? 126.0????? 14234.5?? 1129.7
Shell Scripts (1 concurrent)???????????????????? 42.4?????? 6040.8?? 1424.7
Shell Scripts (8 concurrent)????????????????????? 6.0??????? 717.4?? 1195.7
System Call Overhead????????????????????????? 15000.0??? 2149194.4?? 1432.8
?????????????????????????????????????????????????????????????????? ========
System Benchmarks Index Score??????????????????????????????????????? 1464.1

比較

綜合得分

綁定 1464.1? 不綁定 1444.7

綜合得分 性能提升 1.34%

浮點運算

綁定 3928.7? 不綁定? 3880.4

浮點運算 性能提升 1.24%

轉載于:https://www.cnblogs.com/tcicy/p/10187372.html

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