/proc/cpuinfo doesn't show CPU frequency at all

/proc/cpuinfo doesn't show CPU frequency at all.

I built the kernel on my own. Did I miss some kernel configuration?

pi@raspberrypi ~ $ cat /proc/cpuinfo 
processor   : 0
model name  : ARMv6-compatible processor rev 7 (v6l)
Features    : swp half thumb fastmult vfp edsp java tls 
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part    : 0xb76
CPU revision    : 7

Hardware    : BCM2708
Revision    : 000e
Serial      : 000000009b0dee2f

Kernel version.

pi@raspberrypi ~ $ uname -a
Linux raspberrypi 3.12.9+ #3 PREEMPT Fri Mar 28 16:20:08 KST 2014 armv6l GNU/Linux

Younggun Kim

Posted 2014-03-28T09:21:59.263

Reputation: 153

Answers

This is expected behavior, it's an architecture-dependent feature. Embedded Linux doesn't provide this info, most likely because the CPUs don't.

Here's an example from a router of mine:

system type             : Atheros AR7161 rev 2
machine                 : NETGEAR WNDR3700/WNDR3800/WNDRMAC
processor               : 0
cpu model               : MIPS 24Kc V7.4
BogoMIPS                : 452.19
wait instruction        : yes
microsecond timers      : yes
tlb_entries             : 16
extra interrupt vector  : yes
hardware watchpoint     : yes, count: 4, address/irw mask: [0x0000, 0x0f98, 0x0f78, 0x0df8]
ASEs implemented        : mips16
shadow register sets    : 1
kscratch registers      : 0
core                    : 0
VCED exceptions         : not available
VCEI exceptions         : not available

Daniel B

Posted 2014-03-28T09:21:59.263

Reputation: 40 502

1In case you're interested, see arch/mips/kernel/proc.c in the kernel source. This answer is right: there's no code there to print the CPU frequency. – Flup – 2014-03-28T10:07:36.527

I found BogoMIPS at @daniel-b shows above but not mine. Is this expected behavior too? – Younggun Kim – 2014-03-28T11:45:38.640

Yes, the whole output is architecture-dependent. The processor ID is probably the only universally present field. My router's architecture is MIPS, while your Raspberry Pi's architecture is ARM. – Daniel B – 2014-03-28T11:59:38.030

CPU frequency information can alternatively be found in /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq and other files in /sys/devices/system/cpu/cpu0/cpufreq.

Vortexfive

Posted 2014-03-28T09:21:59.263

Reputation: 148