# [SOLVED] dual core not recognized atom270

## bugmenot

hello!

i can't get the kernel to recognize both my cores. only one core is recognized.

i'm trying to merge an old kernel version

the last version i remember that recognized both my cores was 2.6.34

i had this problem once when upgrading to 2.6.35 and downgrading to 2.6.34 solved my problem

but (after a recent fresh install) it's no longer in the portage tree. is there any way i can get it?

thanks in advance!

here's my .config in case someone has a solution to getting the newer kernels to recognize both cores

http://pastebin.com/8DHNTEn6Last edited by bugmenot on Wed Jun 08, 2011 3:39 pm; edited 2 times in total

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## DawgG

 *Quote:*   

> s there any way i can get it?

 

www.kernel.org (w/out the gentoo-patches)

but it is no problem to use smp-systems with newer kernel-versions, just choose the options accordingly:

```
orbb ~ # uname -rv && zcat /proc/config.gz | grep -E 'SMP|CPUS'

2.6.36-gentoo-r5 #7 SMP Thu Feb 17 14:36:00 CET 2011

CONFIG_USE_GENERIC_SMP_HELPERS=y

CONFIG_X86_64_SMP=y

CONFIG_SMP=y

CONFIG_NR_CPUS=8

CONFIG_SPLIT_PTLOCK_CPUS=4
```

if you 

```
make menuconfig
```

 this is in the section "Processor type and features"; you have to enable Symmetric multi-processing support and set the Maximum number of CPUs (N) (and maybe some other important options) further below.

GOOD LUCK!

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## bugmenot

hello and thank you for your time

i've enabled those options for a 32 bit system (SMP & ACPI)

using the exact same .config the kernel stopped recognizing two cores and simply downgrading to 2.6.34 with an identical .config once more solved the problem

cat .config | grep -E 'SMP|CPUS|ACPI'

```

CONFIG_X86_32_SMP=y

CONFIG_CPUSETS=y

CONFIG_PROC_PID_CPUSET=y

CONFIG_USE_GENERIC_SMP_HELPERS=y

CONFIG_SMP=y

# CONFIG_X86_BIGSMP is not set

CONFIG_NR_CPUS=2

CONFIG_SPLIT_PTLOCK_CPUS=4

CONFIG_PM_SLEEP_SMP=y

CONFIG_HAVE_TEXT_POKE_SMP=y

CONFIG_X86_32_SMP=y

CONFIG_CPUSETS=y

CONFIG_PROC_PID_CPUSET=y

CONFIG_USE_GENERIC_SMP_HELPERS=y

CONFIG_SMP=y

# CONFIG_X86_BIGSMP is not set

CONFIG_NR_CPUS=2

CONFIG_SPLIT_PTLOCK_CPUS=4

# Power management and ACPI options

CONFIG_PM_SLEEP_SMP=y

CONFIG_ACPI=y

CONFIG_ACPI_SLEEP=y

CONFIG_ACPI_PROCFS=y

CONFIG_ACPI_PROCFS_POWER=y

CONFIG_ACPI_POWER_METER=y

# CONFIG_ACPI_EC_DEBUGFS is not set

CONFIG_ACPI_PROC_EVENT=y

CONFIG_ACPI_AC=y

CONFIG_ACPI_BATTERY=y

CONFIG_ACPI_BUTTON=y

CONFIG_ACPI_VIDEO=y

CONFIG_ACPI_FAN=y

CONFIG_ACPI_DOCK=y

CONFIG_ACPI_PROCESSOR=y

CONFIG_ACPI_HOTPLUG_CPU=y

CONFIG_ACPI_PROCESSOR_AGGREGATOR=y

CONFIG_ACPI_THERMAL=y

# CONFIG_ACPI_CUSTOM_DSDT is not set

CONFIG_ACPI_BLACKLIST_YEAR=0

# CONFIG_ACPI_DEBUG is not set

# CONFIG_ACPI_PCI_SLOT is not set

CONFIG_ACPI_CONTAINER=y

# CONFIG_ACPI_SBS is not set

# CONFIG_ACPI_HED is not set

# CONFIG_ACPI_APEI is not set

CONFIG_X86_ACPI_CPUFREQ=y

# CONFIG_HOTPLUG_PCI_ACPI is not set

CONFIG_HAVE_TEXT_POKE_SMP=y

CONFIG_PNPACPI=y

CONFIG_ATA_ACPI=y

# CONFIG_PATA_ACPI is not set

# ACPI drivers

# ACPI drivers

# CONFIG_THINKPAD_ACPI is not set

# CONFIG_ACPI_WMI is not set

CONFIG_ACPI_ASUS=y

# CONFIG_ACPI_TOSHIBA is not set

# CONFIG_ACPI_CMPC is not set

CONFIG_USE_GENERIC_SMP_HELPERS=y

CONFIG_X86_32_SMP=y

CONFIG_CPUSETS=y

CONFIG_PROC_PID_CPUSET=y

CONFIG_SMP=y

# CONFIG_X86_BIGSMP is not set

CONFIG_NR_CPUS=2

CONFIG_SPLIT_PTLOCK_CPUS=4

# Power management and ACPI options

CONFIG_PM_SLEEP_SMP=y

CONFIG_ACPI=y

CONFIG_ACPI_SLEEP=y

CONFIG_ACPI_PROCFS=y

CONFIG_ACPI_PROCFS_POWER=y

# CONFIG_ACPI_POWER_METER is not set

# CONFIG_ACPI_EC_DEBUGFS is not set

CONFIG_ACPI_PROC_EVENT=y

CONFIG_ACPI_AC=y

CONFIG_ACPI_BATTERY=y

CONFIG_ACPI_BUTTON=y

CONFIG_ACPI_VIDEO=y

CONFIG_ACPI_FAN=y

CONFIG_ACPI_DOCK=y

CONFIG_ACPI_PROCESSOR=y

CONFIG_ACPI_HOTPLUG_CPU=y

# CONFIG_ACPI_PROCESSOR_AGGREGATOR is not set

CONFIG_ACPI_THERMAL=y

# CONFIG_ACPI_CUSTOM_DSDT is not set

CONFIG_ACPI_BLACKLIST_YEAR=0

# CONFIG_ACPI_DEBUG is not set

# CONFIG_ACPI_PCI_SLOT is not set

CONFIG_ACPI_CONTAINER=y

# CONFIG_ACPI_SBS is not set

# CONFIG_ACPI_HED is not set

# CONFIG_ACPI_APEI is not set

CONFIG_X86_ACPI_CPUFREQ=y

# CONFIG_HOTPLUG_PCI_ACPI is not set

CONFIG_HAVE_TEXT_POKE_SMP=y

CONFIG_PNPACPI=y

CONFIG_ATA_ACPI=y

# CONFIG_PATA_ACPI is not set

# ACPI drivers

# ACPI drivers

# CONFIG_THINKPAD_ACPI is not set

# CONFIG_ACPI_WMI is not set

# CONFIG_ACPI_ASUS is not set

# CONFIG_ACPI_TOSHIBA is not set

# CONFIG_ACPI_CMPC is not set

```

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## DawgG

well SMP MUST work with the current kernel. depending on yout cpu you might have to activate hyperthreading or sth like it.

have you tried copying the .config of 2.6.34 into the directory containing 2.6.39 and running 

```
make oldconfig
```

GOOD LUCK!

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## bugmenot

i don't have the config i used with 2.6.34 as i've since done a fresh install

i believe that the atom 270 has a single physical core running two threads.

i'll keep looking and trying different configurations

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## bugmenot

this configuration solved my problem:

cat .config | grep -E 'SMP|CPUS|ACPI' 

```

CONFIG_USE_GENERIC_SMP_HELPERS=y

CONFIG_X86_32_SMP=y

CONFIG_SMP=y

# CONFIG_X86_BIGSMP is not set

CONFIG_NR_CPUS=4

CONFIG_SPLIT_PTLOCK_CPUS=4

# Power management and ACPI options

CONFIG_PM_SLEEP_SMP=y

CONFIG_ACPI=y

CONFIG_ACPI_SLEEP=y

CONFIG_ACPI_PROCFS=y

CONFIG_ACPI_PROCFS_POWER=y

# CONFIG_ACPI_POWER_METER is not set

# CONFIG_ACPI_EC_DEBUGFS is not set

CONFIG_ACPI_PROC_EVENT=y

CONFIG_ACPI_AC=y

CONFIG_ACPI_BATTERY=y

CONFIG_ACPI_BUTTON=y

CONFIG_ACPI_VIDEO=y

CONFIG_ACPI_FAN=y

CONFIG_ACPI_DOCK=y

CONFIG_ACPI_PROCESSOR=y

CONFIG_ACPI_HOTPLUG_CPU=y

# CONFIG_ACPI_PROCESSOR_AGGREGATOR is not set

CONFIG_ACPI_THERMAL=y

# CONFIG_ACPI_CUSTOM_DSDT is not set

CONFIG_ACPI_BLACKLIST_YEAR=0

# CONFIG_ACPI_DEBUG is not set

# CONFIG_ACPI_PCI_SLOT is not set

CONFIG_ACPI_CONTAINER=y

# CONFIG_ACPI_SBS is not set

# CONFIG_ACPI_HED is not set

# CONFIG_ACPI_APEI is not set

CONFIG_X86_ACPI_CPUFREQ=y

# CONFIG_HOTPLUG_PCI_ACPI is not set

CONFIG_HAVE_TEXT_POKE_SMP=y

CONFIG_PNPACPI=y

CONFIG_ATA_ACPI=y

# CONFIG_PATA_ACPI is not set

# ACPI drivers

# ACPI drivers

# CONFIG_THINKPAD_ACPI is not set

# CONFIG_ACPI_WMI is not set

# CONFIG_ACPI_ASUS is not set

# CONFIG_ACPI_TOSHIBA is not set

# CONFIG_ACPI_CMPC is not set

```

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