# Core i7, only one core showing [SOLVED]

## audiodef

I have a Core i7 on a remote server. There should be four cores, but /proc/cpuinfo is only reporting one. 

Here is my kernel config. 

Here is dmesg | grep cpu:

```

[    0.000000] Initializing cgroup subsys cpuset

[    0.000000] Initializing cgroup subsys cpu

[    0.000000] Initializing cgroup subsys cpuacct

[    0.000000] setup_percpu: NR_CPUS:64 nr_cpumask_bits:64 nr_cpu_ids:1 nr_node_ids:1

[    0.000000] PERCPU: Embedded 33 pages/cpu @ffff88063fc00000 s94360 r8192 d32616 u2097152

[    0.000000] pcpu-alloc: s94360 r8192 d32616 u2097152 alloc=1*2097152

[    0.000000] pcpu-alloc: [0] 0 

[    0.000000]    RCU restricting CPUs from NR_CPUS=64 to nr_cpu_ids=1.

[    0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1

[    0.226502] cpuidle: using governor ladder

[    0.226639] cpuidle: using governor menu

[    0.250877] HPET: 4 timers in total, 0 timers will be used for per-cpu timer

[   25.733863]  [<ffffffff810e6e87>] ? acct_account_cputime+0x17/0x20

```

cat /proc/cpuinfo:

```

processor   : 0

vendor_id   : GenuineIntel

cpu family   : 6

model      : 26

model name   : Intel(R) Core(TM) i7 CPU         930  @ 2.80GHz

stepping   : 5

microcode   : 0x11

cpu MHz      : 2806.972

cache size   : 8192 KB

physical id   : 0

siblings   : 1

core id      : 0

cpu cores   : 1

apicid      : 0

initial apicid   : 0

fpu      : yes

fpu_exception   : yes

cpuid level   : 11

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 rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid

bugs      :

bogomips   : 5613.94

clflush size   : 64

cache_alignment   : 64

address sizes   : 36 bits physical, 48 bits virtual

power management:

```

What am I missing?

----------

## Keruskerfuerst

I think you should add SMP support.

And eventually Hyperthreading support.

----------

## dweezil-n0xad

Did you boot the kernel with acpi=off ? 

acpi=off allows the system to boot normally, but only with 1 core enabled.

----------

## audiodef

SMP and HT are enabled - it's right there in the config I posted. I'm not booting with APCI off.

----------

## NeddySeagoon

audiodef,

I don't see anything in your kernel.  Maybe there will be a hint in dmesg?

----------

## audiodef

I'm not sure what I'm looking at in dmesg | grep cpu in the OP, but here's the entire dmesg.

----------

## NeddySeagoon

audiodef,

I don't know what I'm looking for either ...  but,

I've not seen all those 

```
[    0.000000] ACPI Error: Resize of Root Table Array is not allowed (20150410/tbdata-444)
```

entries before

```
Line 461 [    0.000000] smpboot: Allowing 1 CPUs, 0 hotplug CPUs
```

looks bad too and the kernel has hardly done anything yet.

```
[    0.000416] ACPI: Core revision 20150410

[    0.000571] ACPI Exception: AE_NO_ACPI_TABLES, While loading namespace from ACPI tables (20150410/tbxfload-80)

[    0.000888] ACPI: Unable to load the System Description Tables
```

```
[    0.019331] smpboot: weird, boot CPU (#0) not listed by the BIOS

[    0.019470] smpboot: SMP motherboard not detected

[    0.019606] smpboot: SMP disabled
```

Then its all over.

I don't know that its connected to the ACPI errors.

----------

## audiodef

Hm, looks like I have no choice but to ask Hetzner support to physically check the machine, maybe see if something in the BIOS is not set properly.

----------

## toralf

 *audiodef wrote:*   

> Hm, looks like I have no choice but to ask Hetzner support

 I've an i7 at Hetzner too, FWIW here's my .config (stable hardened gentoo Linux kernel) : https://bpaste.net/show/c459b80b1770

----------

## audiodef

Thanks! I'll diff this with mine and see what comes up.

A little off-topic, but for some reason, hardened-4.3 fails on me no matter what I do, but 4.1 worked on the first try. 

 *toralf wrote:*   

>  *audiodef wrote:*   Hm, looks like I have no choice but to ask Hetzner support I've an i7 at Hetzner too, FWIW here's my .config (stable hardened gentoo Linux kernel) : https://bpaste.net/show/c459b80b1770

 

EDIT:

The diff shows nothing for SMP and HT, which just confirms that those options are correctly enabled. Thanks again.  :Smile: 

Hetzner is checking my server. They are quite fast. I made a support request not 20 minutes ago and they've already asked my permission to shut down the server so they can check it.

----------

## toralf

Hhm, for the hardened kernel I just choosed a vanilla .config and selected CONFIG_GRKERNSEC_CONFIG_SERVER=y 

```
$>uname -a

Linux ms-magpie 4.3.3-hardened-r7 #1 SMP Wed Jan 20 15:06:09 CET 2016 x86_64 Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz GenuineIntel GNU/Linux

```

----------

## audiodef

I checked that option in 4.1 and it's not selected by default. Maybe 4.3 requires it. Which is the latest ~stable, though, 4.1 or 4.3?

 *toralf wrote:*   

> Hhm, for the hardened kernel I just choosed a vanilla .config and selected CONFIG_GRKERNSEC_CONFIG_SERVER=y 
> 
> ```
> $>uname -a
> 
> ...

 

----------

## audiodef

It was the BIOS. Hetzner fixed it. All eight cores are now showing. I thought I had four, but can't complain!

----------

## toralf

 *audiodef wrote:*   

> It was the BIOS. Hetzner fixed it. All eight cores are now showing. I thought I had four, but can't complain!

 4 physical ==  8 threads

----------

## audiodef

So what exactly is cat /proc/cpuinfo showing with entries 0-7?

----------

## NeddySeagoon

audiodef,

Four physical cores and four hyperthreading cores.

Each physical core supports two (hyper)threads, so it looks like two cores.

It helps CPU throughput under some workloads and makes it worse under others.

When hyperthreading was new, on a real world system, which I no longer have access to, it halved throughput.

We turned hyperthreading off in the BIOS.  That was a few years ago now though.

----------

## audiodef

Got it. Thanks, Neddy.

So should I use -j5 or -j9 for MAKEOPTS?

----------

## NeddySeagoon

audiodef,

-j9 is a good place to start.

----------

## Keruskerfuerst

Makeopts="-j8"

----------

## audiodef

Thanks, Neddy and Keruskerfuerst.

----------

## Keruskerfuerst

Can you enable virtualization in the Bios?

Then enable virtualization in the kernel, too.

----------

## toralf

 *NeddySeagoon wrote:*   

> audiodef,
> 
> -j9 is a good place to start.

 I made good experiences with <amount + threads -1> mreaning -j7 in this case

----------

