• Jiri Olsa's avatar
    tracing/latency: Fix header output for latency tracers · 7e9a49ef
    Jiri Olsa authored
    In case the the graph tracer (CONFIG_FUNCTION_GRAPH_TRACER) or even the
    function tracer (CONFIG_FUNCTION_TRACER) are not set, the latency tracers
    do not display proper latency header.
    
    The involved/fixed latency tracers are:
            wakeup_rt
            wakeup
            preemptirqsoff
            preemptoff
            irqsoff
    
    The patch adds proper handling of tracer configuration options for latency
    tracers, and displaying correct header info accordingly.
    
    * The current output (for wakeup tracer) with both graph and function
      tracers disabled is:
    
      # tracer: wakeup
      #
        <idle>-0       0d.h5    1us+:      0:120:R   + [000]     7:  0:R watchdog/0
        <idle>-0       0d.h5    3us+: ttwu_do_activate.clone.1 <-try_to_wake_up
        ...
    
    * The fixed output is:
    
      # tracer: wakeup
      #
      # wakeup latency trace v1.1.5 on 3.1.0-tip+
      # --------------------------------------------------------------------
      # latency: 55 us, #4/4, CPU#0 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:2)
      #    -----------------
      #    | task: migration/0-6 (uid:0 nice:0 policy:1 rt_prio:99)
      #    -----------------
      #
      #                  _------=> CPU#
      #                 / _-----=> irqs-off
      #                | / _----=> need-resched
      #                || / _---=> hardirq/softirq
      #                ||| / _--=> preempt-depth
      #                |||| /     delay
      #  cmd     pid   ||||| time  |   caller
      #     \   /      |||||  \    |   /
           cat-1129    0d..4    1us :   1129:120:R   + [000]     6:  0:R migration/0
           cat-1129    0d..4    2us+: ttwu_do_activate.clone.1 <-try_to_wake_up
    
    * The current output (for wakeup tracer) with only function
      tracer enabled is:
    
      # tracer: wakeup
      #
           cat-1140    0d..4    1us+:   1140:120:R   + [000]     6:  0:R migration/0
           cat-1140    0d..4    2us : ttwu_do_activate.clone.1 <-try_to_wake_up
    
    * The fixed output is:
      # tracer: wakeup
      #
      # wakeup latency trace v1.1.5 on 3.1.0-tip+
      # --------------------------------------------------------------------
      # latency: 207 us, #109/109, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:2)
      #    -----------------
      #    | task: watchdog/1-12 (uid:0 nice:0 policy:1 rt_prio:99)
      #    -----------------
      #
      #                  _------=> CPU#
      #                 / _-----=> irqs-off
      #                | / _----=> need-resched
      #                || / _---=> hardirq/softirq
      #                ||| / _--=> preempt-depth
      #                |||| /     delay
      #  cmd     pid   ||||| time  |   caller
      #     \   /      |||||  \    |   /
        <idle>-0       1d.h5    1us+:      0:120:R   + [001]    12:  0:R watchdog/1
        <idle>-0       1d.h5    3us : ttwu_do_activate.clone.1 <-try_to_wake_up
    
    Link: http://lkml.kernel.org/r/20111107150849.GE1807@m.brq.redhat.com
    
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Signed-off-by: default avatarJiri Olsa <jolsa@redhat.com>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    7e9a49ef
trace.h 23.6 KB