• Len Brown's avatar
    tools/power: turbostat v2 - re-write for efficiency · c98d5d94
    Len Brown authored
    
    
    Measuring large profoundly-idle configurations
    requires turbostat to be more lightweight.
    Otherwise, the operation of turbostat itself
    can interfere with the measurements.
    
    This re-write makes turbostat topology aware.
    Hardware is accessed in "topology order".
    Redundant hardware accesses are deleted.
    Redundant output is deleted.
    Also, output is buffered and
    local RDTSC use replaces remote MSR access for TSC.
    
    From a feature point of view, the output
    looks different since redundant figures are absent.
    Also, there are now -c and -p options -- to restrict
    output to the 1st thread in each core, and the 1st
    thread in each package, respectively.  This is helpful
    to reduce output on big systems, where more detail
    than the "-s" system summary is desired.
    Finally, periodic mode output is now on stdout, not stderr.
    
    Turbostat v2 is also slightly more robust in
    handling run-time CPU online/offline events,
    as it now checks the actual map of on-line cpus rather
    than just the total number of on-line cpus.
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    c98d5d94
turbostat.c 34 KB