Obtaining the CPU frequency

To put it simply, if the info isn't available in a syscall, you can't get it except from the logs of the bootup or proc (where what the kernel thinks it is is stored, right or wrong). The clock speed isn't exported from a cpu in general! You might get it from a bios call, sometimes. But certainly up to at least 686 one couldn't get anything but a good guess or a range. The other possibility is to time it yourself, as I said. You have the bogomips code. You can get the cpu id. With a table you should be able to figure the main clock frequency.

% bogomips Calibrating delay loop.. ok - 442.00 BogoMips

% catproc-cpuinfo processor : 0 vendorid : GenuineIntel cpu family : 6 model : 6 model name : Celeron (Mendocino) stepping : 0 cpu MHz : 451.031 cache size : 128 KB fdivbug : no hltbug : no f00fbug : no comabug : no fpu : yes fpuexception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr bogomips : 888.83

Guess somebody does faster loops in kernelspace!

Peter