• Taeung Song's avatar
    perf ftrace: Add ftrace.tracer config option · b05d1093
    Taeung Song authored
    Currently 'perf ftrace' command allows selecting 'function_graph' or
    'function', defaulting to 'function_graph'.
    
    Add ftrace.tracer config option to select the default tracer:
    
        # cat ~/.perfconfig
        [ftrace]
            tracer = function
    
        # perf ftrace usleep 123456 | head -10
          <...>-14450 [002] d... 10089.284231: finish_task_switch <-__schedule
          <...>-14450 [002] .... 10089.284232: finish_wait <-pipe_wait
          <...>-14450 [002] .... 10089.284232: mutex_lock <-pipe_wait
          <...>-14450 [002] .... 10089.284232: _cond_resched <-mutex_lock
    
    Committer notes:
    
    Retesting it with invalid variables, invalid values for ftrace.tracer,
    and a valid one:
    
      # cat ~/.perfconfig
      [ftrace]
            trace = function
      # perf ftrace usleep 1
      Error: wrong config key-value pair ftrace.trace=function
      # cat ~/.perfconfig
      [ftrace]
            tracer = functin
      # perf ftrace usleep 1
      Please select "function_graph" (default) or "function"
      Error: wrong config key-value pair ftrace.tracer=functin
      # cat ~/.perfconfig
      [ftrace]
            tracer = function
      # perf ftrace usleep 1 | head -5
              <idle>-0     [000] d...  3855.820847: switch_mm_irqs_off <-__schedule
               <...>-18550 [000] d...  3855.820849: finish_task_switch <-__schedule
               <...>-18550 [000] d...  3855.820851: smp_irq_work_interrupt <-irq_work_interrupt
               <...>-18550 [000] d...  3855.820851: irq_enter <-smp_irq_work_interrupt
               <...>-18550 [000] d...  3855.820851: rcu_irq_enter <-irq_enter
      #
    Signed-off-by: default avatarTaeung Song <treeze.taeung@gmail.com>
    Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Wang Nan <wangnan0@huawei.com>
    Link: http://lkml.kernel.org/r/1485862711-20216-3-git-send-email-treeze.taeung@gmail.com
    [ Added missign space in error message, changed the logic to make it more compact and less error prone ]
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    b05d1093
builtin-ftrace.c 5.44 KB