Re: bizarre 2.6.8.1 /sys permissions

[Bill Davidsen <davidsen@tmr.com>]

Dave Jones wrote:
> On Wed, Aug 25, 2004 at 04:31:50PM -0700, Dan Hollis wrote:
>  > >  > $ cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
>  > >  > cat: /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq: Permission denied
>  > > Reading this file causes reads from hardware on some cpufreq drivers.
>  > > This can be a slow operation, so a user could degrade system performance
>  > > for everyone else by repeatedly cat'ing it.
>  > 
>  > any reason why cpuinfo_cur_freq cant read cpu_khz ?
> 
> cpufreq_cur_freq will be one of scaling_available_frequencies.
> These are usually a value such as 1300MHz, where cpu_mhz is a
> 'measured' value and will look something like 1303.852
> 
> the values cpufreq uses are the values either returned by the
> hardware as its settable states, or from BIOS tables defining
> those states.
> 
>  > or rather, is there any reason why cpuinfo_cur_freq and /proc/cpuinfo 
>  > should legitimately differ?
> 
> They aren't identical, and serve different purposes.

Okay, so cpufreq just gives informational values in a table while 
/proc/cpuinfo actually reflects the speed of the CPU. Right? That's 
good, I thought there was an problem if they were different.

-- 
    -bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
  last possible moment - but no longer"  -me