Signed-off-by: Thomas Renninger <trenn@xxxxxxx> Cc: <linux-acpi@xxxxxxxxxxxxxxx> Cc: "Pallipadi, Venkatesh" <venkatesh.pallipadi@xxxxxxxxx> Cc: <cpufreq@xxxxxxxxxxxxxxx> --- Documentation/cpu-freq/cpufreq-stats.txt | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-) diff --git a/Documentation/cpu-freq/cpufreq-stats.txt b/Documentation/cpu-freq/cpufreq-stats.txt index fc64749..aa05b65 100644 --- a/Documentation/cpu-freq/cpufreq-stats.txt +++ b/Documentation/cpu-freq/cpufreq-stats.txt @@ -44,11 +44,28 @@ the stats driver insertion. total 0 drwxr-xr-x 2 root root 0 May 14 16:06 . drwxr-xr-x 3 root root 0 May 14 15:58 .. +-r--r--r-- 1 root root 4096 May 14 16:06 average_freq -r--r--r-- 1 root root 4096 May 14 16:06 time_in_state -r--r--r-- 1 root root 4096 May 14 16:06 total_trans -r--r--r-- 1 root root 4096 May 14 16:06 trans_table -------------------------------------------------------------------------------- +- average_freq +Shows the average frequency the processor stayed in since the file was read +the last time. Zero is shown if it is read the first time or "not supported". + +CONFIG_X86_AVERAGE_FREQUENCY=y config needs to be set and the processor must +support overclocking of single cores (ida flag in /proc/cpuinfo). +This is the only way to detect, monitor and optimze for the feature that the +BIOS can overclock single CPU cores behind the kernel's back if thermal +requirements are met (e.g. other cores of the socket run at low frequency or +sleep). + +Also on multi-core processors the shown current CPU frequency the machine is +running on in cpufreq/cpufreq_scaling_cur and /proc/cpuinfo can be wrong with +current kernels if the frequency of several cores must be the same because of +HW restritions. average_freq should show the real frequency. + - time_in_state This gives the amount of time spent in each of the frequencies supported by this CPU. The cat output will have "<frequency> <time>" pair in each line, which -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
