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    SubjectRe: [PATCH 5/5] cpufreq: Add support for actual freq
    Hey,

    On Tue, Mar 23, 2010 at 03:23:49PM +0100, Borislav Petkov wrote:
    > > scaling_cur freq should show the frequency the kernel/cpufreq
    > > subsystem thinks it's in.
    >
    > Well, we have also
    > /sys/devices/system/cpu/cpu<NUM>/cpufreq/cpuinfo_cur_freq and it reads
    > also policy->cur.

    No. cpuinfo_cur_freq calls __cpufreq_get() which itself calls the driver's
    ->get() callback, which is exactly for determining the current frequency. I
    assume CPUFREQ_CONST_LOOP is set, else we'd get into trouble; but as long as
    that's the case I see no problem in using ->get() / cpuinfo_cur_freq to read
    out the current actual frequency.

    > Why not show the actual frequency in scaling_cur_freq then?

    Quoting Documentation/cpu-freq/user-guide.txt :

    cpuinfo_cur_freq : Current frequency of the CPU as obtained from
    the hardware, in KHz. This is the frequency
    the CPU actually runs at.

    scaling_cur_freq : Current frequency of the CPU as determined by
    the governor and cpufreq core, in KHz. This is
    the frequency the kernel thinks the CPU runs
    at.

    So scaling_cur_freq may not be mis-used for this; cpuinfo_cur_freq may be
    used for it, though. IMVHO.

    Best,
    Dominik


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