Re: Used Cores / Threads CPU E3-1230 V2

On 4/5/22 6:29 PM, Heiko wrote:
> Hello List,
>
> I use a Xeon(R) CPU E3-1230 V2 on bios0: Supermicro X9SCL/X9SCM
> This is a 4 Core 8 Threads cpu.
>
> In dmesg, cpu0 to cpu7 are displayed as follows:
> cpu0 at mainbus0: apid 0 (boot processor)
> cpu0: Intel(R) Xeon(R) CPU E3-1230 V2 @ 3.30GHz, 3300.47 MHz,
> 06-3a-09
> cpu0: FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,
> ... MELTDOWN
> cpu0: 256KB 64b/line 8-way L2 cache
> cpu0: apic clock running at 100MHz
> cpu0: mwait min=64, max=64, C-substates=0.2.1.1, IBE
> cpu at mainbus0: not configured
>
> Now I'm a bit confused about the views in top and htop.
>
> top shows me cpu0 to cpu3.
>
> htop shows me 1 to 8, but 5 to 8 is shown as "offline"
>
> It is (uname -a): OpenBSD user@host 7.1 GENERIC.MP#461 amd64
> and some kernels before.
>
> Now my question, in "top" only the physical cores are displayed.
> In "htop" all that are also shown in dmesg.
>
> But why are the cpu4 to cpu8 displayed as "offline".
> Is really only cpu0 to cpu3 used and not cpu4 to cpu7,
> how can I interpret that correctly?
>
> Thank you for the clarification in advance.
> /Heiko
>

It is my understanding that HT/SMT is disabled in OpenBSD by default. A
web search about that should give you more info.