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sysfs cpufreq missing in 2.6.0

DISCUSSION Nirmal Govind 5 participants 7 messages Dec 23, 2003 – Jan 9, 2004

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#0 lore raw

Hi,

I compiled the 2.6.0 kernel (released on Dec. 18, downloaded from kernel.org) with the options enabled for userspace cpufreq.. the documentation says that sysfs will be used however I do not have any such device in /proc/sys/ or in /. I enabled the /proc/cpufreq so I do see a /proc/cpufreq but nothing similar to /sys/devices/system/cpu/cpu0/cpufreq/ as mentioned in the kernel documentation which also says that the sysfs devices will be created automatically. Here's what my /proc/sys/ looks like:

root@variance:~# ls /proc/sys
abi/  debug/  dev/  fs/  kernel/  net/  proc/  sunrpc/  vm/

Below is the relevant config options in the kernel (the default on boot is set to userspace). Please let me know if I'm missing something and if there's some way to get the cpufreq working with sysfs.

Thanks,
nirmal

--

#
# CPU Frequency scaling
#
CONFIG_CPU_FREQ=y CONFIG_CPU_FREQ_PROC_INTF=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE=y CONFIG_CPU_FREQ_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_POWERSAVE=y CONFIG_CPU_FREQ_GOV_USERSPACE=y
# CONFIG_CPU_FREQ_24_API is not set CONFIG_CPU_FREQ_TABLE=y

#
# CPUFreq processor drivers
#
# CONFIG_X86_ACPI_CPUFREQ is not set
# CONFIG_X86_POWERNOW_K6 is not set
# CONFIG_X86_POWERNOW_K7 is not set
# CONFIG_X86_POWERNOW_K8 is not set
# CONFIG_X86_GX_SUSPMOD is not set
CONFIG_X86_SPEEDSTEP_CENTRINO=y
# CONFIG_X86_SPEEDSTEP_ICH is not set
# CONFIG_X86_SPEEDSTEP_SMI is not set
# CONFIG_X86_P4_CLOCKMOD is not set
# CONFIG_X86_LONGRUN is not set
# CONFIG_X86_LONGHAUL is not set

#1 lore raw
Quoted 7 lines · Nirmal Govind

Hi,

I compiled the 2.6.0 kernel (released on Dec. 18, downloaded from kernel.org) with the options enabled for userspace cpufreq.. the documentation says that sysfs will be used however I do not have any such device in /proc/sys/ or in /. I enabled the /proc/cpufreq so I do see a /proc/cpufreq but nothing similar to

sysfs is not procfs :)
take look at Documentation/filesystems/sysfs.txt in your kernel tree

bye

Signature · 2 lines
mattia
:wq!
#2 lore raw
Quoted 4 lines

sysfs is not procfs :)
take look at Documentation/filesystems/sysfs.txt in your kernel tree

bye

Aah.. thank you! Read it and also found the cpufreq after I mounted sysfs. I changed the frequency too - one question: how does one know if it's actually working? I see the new frequency in the scaling_setspeed file but are there any user tools that show the real-time frequency of the processor?

Thanks,
nirmal

#3 lore raw
Quoted 5 lines · Nirmal Govind

Aah.. thank you! Read it and also found the cpufreq after I mounted sysfs. I changed the frequency too - one question: how does one know if it's actually working? I see the new frequency in the scaling_setspeed file but are there any user tools that show the real-time frequency of the processor?

cat /proc/cpuinfo ....

#4 lore raw
Quoted 3 lines

cat /proc/cpuinfo ....

Yes, I tried that but that still shows the original frequency. So here's what my scaling_setspeed looks like:

root@variance:/# more /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
800000

And here's my /proc/cpuinfo:

root@variance:/usr/src/linux-2.6.0# more /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 9
model name      : Intel(R) Pentium(R) M processor 1400MHz
stepping        : 5
cpu MHz         : 1400.280
cache size      : 1024 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr mce cx8 apic sep mtrr pge mca cmov pat
clflush dts acpi mmx fxsr sse sse2 tm pbe tm2 est
bogomips        : 1493.28

I don't see an 800 here.. I'm pretty sure the frequency has been scaled down since my fan doesn't come on that often now.. or could it be that the machine is fooled into thinking that the freq. is 800 (and hence the reduced fan activity) but it's still actually at 1400? That would be scary and might result in failures I guess...

Thanks,
nirmal

#6 lore raw
In reply to Nirmal Govind
Quoted 10 lines · Nirmal Govind

Hi,

I compiled the 2.6.0 kernel (released on Dec. 18, downloaded from kernel.org) with the options enabled for userspace cpufreq.. the documentation says that sysfs will be used however I do not have any such device in /proc/sys/ or in /. I enabled the /proc/cpufreq so I do see a /proc/cpufreq but nothing similar to /sys/devices/system/cpu/cpu0/cpufreq/ as mentioned in the kernel documentation which also says that the sysfs devices will be created automatically. Here's what my /proc/sys/ looks like:

You have to mount the sysfs in /sys. Create the /sys directory with mkdir, and add this to your /etc/fstab

sysfs /sys sysfs defaults 0 0

and run a mount -a. Then you'll have the new sysfs system mounted.

Hope this helps.

Jan

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#5 lore raw
In reply to AthlonRob
Quoted 10 lines · AthlonRob
Quoted 5 lines · Nirmal Govind

Aah.. thank you! Read it and also found the cpufreq after I mounted sysfs. I changed the frequency too - one question: how does one know if it's actually working? I see the new frequency in the scaling_setspeed file but are there any user tools that show the real-time frequency of the processor?

cat /proc/cpuinfo ....

No. /proc/cpuinfo will only show what 'think' cpufreq internals. Use bogomips instead for example, or eventually x86info.

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