Arch Linux

timothyk.tech

Member

Registered: 2018-07-06

Posts: 9

[SOLVED] CPU pinning/affinity question

Good afternoon,

Im studying CPU pinning because im in the process of building a windows VM to game on. I found a reddit post about cpu pinning but the person's explanation does not make sense to me. He says that core's 0 and 6 are on the same physical core, but the cat output looks like 0 and 4 are. Can someone explain this output or refer me to good docs on this subject? :

Anyhow i have 6 core CPU so i pin 4 cores to VM and leave 2 cores to host. So in your case i guess i would try pinning 3 cores to VM and leaving 1 core to the host. And probably suspending those linux VMs and closing stuff like browser and any other applications that you do not need at that moment.

Figure out sibling cores.:

~ % cat /proc/cpuinfo|grep "core id"
core id         : 0   # core 0, cpu 0
core id         : 1   # core 1, cpu 1
core id         : 2   # core 2, cpu 2
core id         : 3   # core 3, cpu 3
core id         : 0   # core 4, cpu 0
core id         : 1   # core 5, cpu 1
core id         : 2   # core 6, cpu 2
core id         : 3   # core 7, cpu 3

This is a list of logical cores with their physical core id. As you can see core 0 and core 6 belong to same physical core 0. So what i would do is something like this:

Last edited by timothyk.tech (2019-01-07 20:09:13)

loqs

Member

Registered: 2014-03-06

Posts: 17,323

Re: [SOLVED] CPU pinning/affinity question

You are correct 0 and 4 are the hyperthreads of the same physical cpu.
Edit:
If you wish to view it graphically `lstopo`

Last edited by loqs (2019-01-04 17:09:10)

timothyk.tech

Member

Registered: 2018-07-06

Posts: 9

Re: [SOLVED] CPU pinning/affinity question

Thank you very much, Just want to make sure I wasnt missing a concept.

You are correct 0 and 4 are the hyperthreads of the same physical cpu.
Edit:
If you wish to view it graphically `lstopo`