vSphere Hypervisor

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  • 1.  CPU Scheduling Affinity question

    Posted Feb 04, 2021 05:25 AM

    Hi,

    I was using VMware vSphere 6.5. The server has two CPU E5-2620v4 (8 cores). Hyperthreading disabled.

    I set CPU scheduling affinity of one VM as 8-11. After apply it the setting was changed to 10,11,8 automatically.

    How to avoid and debug? Why it's changed unexpectedly?

    Thanks.



  • 2.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 07:07 AM

    Hey ,

    Well you are specifying a range from 8 to 11. So it is expected to have more than one. However I presume you should have the 9 also. How many vCPU do you have on your VM?



  • 3.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 07:35 AM

    Hi  

    I have 4 vCPU on my VM. That's why I set 8-11. I want to have CPU pinning here to keep using those four cores.

    Any idea? Thanks.

     



  • 4.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 07:40 AM

    Could you please confirm here that you do not have any processor disabled from the BIOS?



  • 5.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 07:51 AM

    I'm not aware that BIOS could disable processor? I could not reboot the host now. How could I check in vSphere web GUI?



  • 6.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 08:00 AM

    Any particular reason you use CPU Affinity? As it isn't very common and complicates the environment significantly...



  • 7.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 08:21 AM

    My VM is running DPDK applications. To improve performance, I need to set CPU pinning with scheduling affinity.



  • 8.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 09:11 AM

    Ah okay, you could also try a reservation and enable "latency sensitivity" on the VM if that makes things easier.



  • 9.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 09:18 AM

    Thanks for pointing out the feature. How about CPU pinning with scheduling affinity? Any idea why it's changed unexpectedly?

    Thanks.



  • 10.  RE: CPU Scheduling Affinity question

    Posted Feb 04, 2021 08:38 PM

    I have no idea, I would suggest placing a support request if you have active support.