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#1 2013-09-22 07:23:58

apex
Member
Registered: 2013-09-22
Posts: 29

CPU Cores missing on lscpu - SOLVED get better power supply.

I did a search on this topic both in this forum and other sites, closed thread answers seem to be the same but does not seem to work with my machine for some reason.

When compiling or doing cpu intensive work I discovered arch is not using all the cpu cores.
I heard cold boot can make a difference so  did a reset, post, off button, then on; all cores to showed just once, not since then again.

I have tried using the dozer kernel, still makes no difference.

Will not boot into gui with acpi enabled in the bios.

Tried GRUB_CMDLINE_LINUX="apic=no" and no changes after rebuilding grub and reboot.

Here is my computer config, can/will provide more settings info on request.

OS Info:

Linux apexlinux 3.11.1-1-ARCH #1 SMP PREEMPT Sat Sep 14 19:30:21 CEST 2013 x86_64 GNU/Linux

Machine Specs:

16 GB RAM
120 GB Digital Sata HD - OCZ3
Radeon HD 6570 PCIe Card

lscpu output:

Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                1
On-line CPU(s) list:   0
Thread(s) per core:    1
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             AuthenticAMD
CPU family:            21
Model:                 1
Model name:            AMD FX(tm)-8120 Eight-Core Processor
Stepping:              2
CPU MHz:               1400.000
BogoMIPS:              6202.24
Virtualization:        AMD-V
L1d cache:             16K
L1i cache:             64K
L2 cache:              2048K
L3 cache:              8192K
NUMA node0 CPU(s):     0

Asus motherboard M5A87
bios settings:
ACPI disabled
APCI for APIC diabled


Thanks in advance for anyone that can help.

Last edited by apex (2013-10-01 21:42:24)

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#2 2013-09-22 08:26:56

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

You have to sort out the ACPI problems on your machine. Without ACPI, it's unlikely you'll ever be able to use more than one cpu.

Will not boot into gui with acpi enabled in the bios.

You mean you're able to boot into console/single mode? Start grabbing the kernel logs, then.

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#3 2013-09-22 09:05:11

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Thank you for the reply,

I was able to see more than one cpu core (all 8) with acipi off, but if you say it is related will indeed be open to suggestions.

What i mean by gui is KDE login manager or KDE itself, does the same with XFCE, hangs unless acpi is off in bios.

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#4 2013-09-22 09:22:27

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

ok, strange occurance, acpi and acpi apic is on, system boots normal and woo whoo

Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                8
On-line CPU(s) list:   0-7
Thread(s) per core:    2
Core(s) per socket:    4
Socket(s):             1
NUMA node(s):          1
Vendor ID:             AuthenticAMD
CPU family:            21
Model:                 1
Model name:            AMD FX(tm)-8120 Eight-Core Processor
Stepping:              2
CPU MHz:               1400.000
BogoMIPS:              6202.20
Virtualization:        AMD-V
L1d cache:             16K
L1i cache:             64K
L2 cache:              2048K
L3 cache:              8192K
NUMA node0 CPU(s):     0-7

I have no idea why it started working, this is nutz, any ideas why it was not working previously?

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#5 2013-09-22 09:33:24

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Figured it out,

legacy USB must be set to OFF in bios
plug-n-play set to off
acpi features on in bios
nothing in grub command
both os work with all cpu cores now, thank you very much.

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#6 2013-09-22 12:00:09

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Out of curiosity, can you identify the offending BIOS setting? (I'd bet on the PnP one).

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#7 2013-09-22 12:05:21

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

required both
bios PnP   AND  bios legacy USB must be set to  OFF
All cores show in lscpu but getting crashes with flash player now.

Trying more grub commands to see if i can narrow anything down more.

Will report back when I find the offending monster.

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#8 2013-09-22 12:30:56

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

the following gub command seems to fix the flash issue but now lscpu  only shows ONE CORE again.  Arrrrgggghhhh im going bald over this.

GRUB_CMDLINE_LINUX="nolapic"

I have 8 cores and need all of them, I hope someone out there knows how to fix the flash video problem so all cpu cores can be used.

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#9 2013-09-22 14:10:15

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

The flash issue is unrelated to your (already solved) ACPI/BIOS issue, and playing with the lapic is not the solution.

It's better if you open a dedicated thread, it's probably something related to your video driver/hw assisted video decoding.

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#10 2013-09-22 14:18:55

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

thank you for the comment but if it works with lapic disabled how is that not acpic related?

also seems with javascript disabled and no grub parameters, no crashes but that limits access to sites like hulu or any other site that requires it.

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#11 2013-09-22 14:51:00

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

apex wrote:

thank you for the comment but if it works with lapic disabled how is that not acpic related?

Because disabling lapic disables smp. It's possible that flash is hitting some bug/race condition exposed only on multiprocessor.
Try booting with "maxcpus=1" (or "nosmp") and let's see if it has the same effect of "nolapic".

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#12 2013-09-23 02:10:44

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Thank you, will do, just what i was looking for.

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#13 2013-09-23 10:43:53

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Setting "maxcpus=1"  flash video works flawless
Setting "maxcpus=8"  system reboots in 15 seconds of flash video play

Going to try setting bios cores to automatic with these settings and see what happens.

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#14 2013-09-23 11:18:01

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

ilsensine wrote:
apex wrote:

thank you for the comment but if it works with lapic disabled how is that not acpic related?

Because disabling lapic disables smp. It's possible that flash is hitting some bug/race condition exposed only on multiprocessor.
Try booting with "maxcpus=1" (or "nosmp") and let's see if it has the same effect of "nolapic".

ilsensine

Thank you, that helps narrow things down a bit to see if turning cores on and off by diff methods makes same results.

With everything at default in bios, system reboots at kdm login.

When I disable  "AMD TURBO CORE"  in bios, am able to login.

Grub Setting "nolapic" flash video works flawless
Grub Setting "maxcpus=1"  flash video works flawless
Grub Setting "maxcpus=8"  system reboots in less 15 seconds of flash video play

ANALYSIS: Using all cpu cores does not work with flash video.  I am going to assume there is a possible conflict somewhere between the video card, motherboard/cpu and or drivers. This confirms my suspisions but at a loss to workout the conflict in the system.

Last edited by apex (2013-09-23 11:23:12)

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#15 2013-09-23 12:03:56

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

When I disable  "AMD TURBO CORE"  in bios, am able to login.

Does this also fix the stability of the flash player?

I am going to assume there is a possible conflict somewhere between the video card, motherboard/cpu and or drivers

If you're using the open source radeon driver, I'd also think about the UVD video decoder. The UVD code is rather new and probably still affected by some bugs (I was hit by one of these bugs too, during 3.10.x). You can exclude problems on the UVD side simply running an older kernel (<= 3.9) and checking if the problems still persist.

Last edited by ilsensine (2013-09-23 12:04:36)

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#16 2013-09-23 12:08:57

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Grub Setting "maxcpus=6"     I can get 8 minutes of flash video on both screens before it reboots

Grub Setting "maxcpus=4"    runs flawless, over half an hour of flash video on both screens and still running fine.


This is supposed to be an 8 core, all cpus show up but I notice only 2 cores per socket. 

That is something I should have noticed first. My apologies. I was worried about cpus when what I think I should have noticed was "cores".

It seems that the system only recognizes 2 of the cores but all 8 cpus which seems contridictory or I just don't understand the FX architecture.

lscpu what i think should be there:
Core(s) per socket:    8
Socket(s):             1

----------------------------------------

lscpu real output when set to "maxcpus=4"
Core(s) per socket:    2
Socket(s):             1

How do I get it to read  Core(s) per socket:    8  ?
or is it supposed to be 2 per socket with 4 cpus on each?
this is confusing.

Last edited by apex (2013-09-23 13:29:06)

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#17 2013-09-23 12:11:44

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

ilsensine wrote:

Does this also fix the stability of the flash player?

No, just allows me to login, without it kdm wil not load.

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#18 2013-09-23 12:35:53

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

apex wrote:

How do I get it to read  Core(s) per socket:    8  ?
or is it supposed to be 2 per socket with 4 cpus on each?

According to your lscpu, you have a cpu socket with 4 cores, each core running 2 threads (SMT, the equivalent o Intel HT). Total 8 virtual CPUs seen by the system.

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#19 2013-09-23 12:38:59

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Can you also verify if booting with mem=4G improves something? (just to exclude other causes related to the memory mapping)

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#20 2013-09-23 13:27:55

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

ok, i get it, thanks for explaining,  4 real cores plus 4 virtual =8     should have done more research on this cpu before purchasing, this is a nightmare.

booted grub with    "mem=4G"
Almost instant crash when playing flash video.

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#21 2013-09-23 13:47:25

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

just got a reply from ASUS, they said they do not support linux
this pisses me off, that should be a warning label on the product before purchasing!

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#22 2013-09-23 13:53:18

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

If you use linux DO NOT PURCHASE ASUS PRODUCTS!

As soon as i mentioned linux, the support chat assistant hung up on me.

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#23 2013-09-23 14:13:54

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

Your problem could not be related to the ASUS board itself. Please try to run a kernel <=3.9 in order to exclude issues with UVD (are you using open source radeon driver, do you?). You're experiencing a bug somehow exposed by the number of cores, something difficult to track down in any case.

I also suggest to keep the AMD TURBO CORE facility permanently disabled, until you succeed on fixing your main problem. The performance drop should be very small, if ever noticeable.

Last edited by ilsensine (2013-09-23 14:15:46)

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#24 2013-09-23 14:17:42

apex
Member
Registered: 2013-09-22
Posts: 29

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

experience it with both ATI Catalyst and with Free radeon drivers.

Will try an older kernel and see what happens.

As for AMD TURBO CORE, cant run that at all because x fails to start if I do.

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#25 2013-09-23 14:21:00

ilsensine
Member
Registered: 2013-03-26
Posts: 32

Re: CPU Cores missing on lscpu - SOLVED get better power supply.

apex wrote:

experience it with both ATI Catalyst and with Free radeon drivers.

That's not encouraging.

Can you attach your full dmesg?

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