• Arjan van de Ven's avatar
    tracing: add "power-tracer": C/P state tracer to help power optimization · f3f47a67
    Arjan van de Ven authored
    Impact: new "power-tracer" ftrace plugin
    
    This patch adds a C/P-state ftrace plugin that will generate
    detailed statistics about the C/P-states that are being used,
    so that we can look at detailed decisions that the C/P-state
    code is making, rather than the too high level "average"
    that we have today.
    
    An example way of using this is:
    
     mount -t debugfs none /sys/kernel/debug
     echo cstate > /sys/kernel/debug/tracing/current_tracer
     echo 1 > /sys/kernel/debug/tracing/tracing_enabled
     sleep 1
     echo 0 > /sys/kernel/debug/tracing/tracing_enabled
     cat /sys/kernel/debug/tracing/trace | perl scripts/trace/cstate.pl > out.svg
    Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    f3f47a67
acpi-cpufreq.c 20.1 KB