• Srinivas Pandruvada's avatar
    cpufreq: intel_pstate: Show different max frequency with turbo 3 and HWP · eea033d0
    Srinivas Pandruvada authored
    On HWP platforms with Turbo 3.0, the HWP capability max ratio shows the
    maximum ratio of that core, which can be different than other cores. If
    we show the correct maximum frequency in cpufreq sysfs via
    cpuinfo_max_freq and scaling_max_freq then, user can know which cores
    can run faster for pinning some high priority tasks.
    
    Currently the max turbo frequency is shown as max frequency, which is
    the max of all cores, even if some cores can't reach that frequency
    even for single threaded workload.
    
    But it is possible that max ratio in HWP capabilities is set as 0xFF or
    some high invalid value (E.g. One KBL NUC). Since the actual performance
    can never exceed 1 core turbo frequency from MSR TURBO_RATIO_LIMIT, we
    use this as a bound check.
    Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    eea033d0
intel_pstate.c 64.1 KB