1. 06 Feb, 2013 3 commits
  2. 03 Feb, 2013 1 commit
  3. 01 Feb, 2013 2 commits
    • Steven Rostedt (Red Hat)'s avatar
      tracing: Init current_trace to nop_trace and remove NULL checks · d840f718
      Steven Rostedt (Red Hat) authored
      On early boot up, when the ftrace ring buffer is initialized, the
      static variable current_trace is initialized to &nop_trace.
      Before this initialization, current_trace is NULL and will never
      become NULL again. It is always reassigned to a ftrace tracer.
      
      Several places check if current_trace is NULL before it uses
      it, and this check is frivolous, because at the point in time
      when the checks are made the only way current_trace could be
      NULL is if ftrace failed its allocations at boot up, and the
      paths to these locations would probably not be possible.
      
      By initializing current_trace to &nop_trace where it is declared,
      current_trace will never be NULL, and we can remove all these
      checks of current_trace being NULL which never needed to be
      checked in the first place.
      
      Cc: Dan Carpenter <dan.carpenter@oracle.com>
      Cc: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      d840f718
    • Ingo Molnar's avatar
      Merge tag 'perf-core-for-mingo' of... · 9c4c5fd9
      Ingo Molnar authored
      Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
      
      Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
      
      . Make some POWER7 events available in sysfs, equivalent to
        what was done on x86, from Sukadev Bhattiprolu.
      
      . Add event group view, from Namyung Kim:
      
        To use it, 'perf record' should group events when recording. And then perf
        report parses the saved group relation from file header and prints them
        together if --group option is provided.  You can use 'perf evlist' command to
        see event group information:
      
          $ perf record -e '{ref-cycles,cycles}' noploop 1
          [ perf record: Woken up 2 times to write data ]
          [ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ]
      
          $ perf evlist --group
          {ref-cycles,cycles}
      
        With this example, default perf report will show you each event
        separately like this:
      
          $ perf report
          ...
          # group: {ref-cycles,cycles}
          # ========
          # Samples: 3K of event 'ref-cycles'
          # Event count (approx.): 3153797218
          #
          # Overhead  Command      Shared Object                      Symbol
          # ........  .......  .................  ..........................
              99.84%  noploop  noploop            [.] main
               0.07%  noploop  ld-2.15.so         [.] strcmp
               0.03%  noploop  [kernel.kallsyms]  [k] timerqueue_del
               0.03%  noploop  [kernel.kallsyms]  [k] sched_clock_cpu
               0.02%  noploop  [kernel.kallsyms]  [k] account_user_time
               0.01%  noploop  [kernel.kallsyms]  [k] __alloc_pages_nodemask
               0.00%  noploop  [kernel.kallsyms]  [k] native_write_msr_safe
      
          # Samples: 3K of event 'cycles'
          # Event count (approx.): 3722310525
          #
          # Overhead  Command      Shared Object                     Symbol
          # ........  .......  .................  .........................
              99.76%  noploop  noploop            [.] main
               0.11%  noploop  [kernel.kallsyms]  [k] _raw_spin_lock
               0.06%  noploop  [kernel.kallsyms]  [k] find_get_page
               0.03%  noploop  [kernel.kallsyms]  [k] sched_clock_cpu
               0.02%  noploop  [kernel.kallsyms]  [k] rcu_check_callbacks
               0.02%  noploop  [kernel.kallsyms]  [k] __current_kernel_time
               0.00%  noploop  [kernel.kallsyms]  [k] native_write_msr_safe
      
        In this case the event group information will be shown in the end of
        header area.  So you can use --group option to enable event group view.
      
          $ perf report --group
          ...
          # group: {ref-cycles,cycles}
          # ========
          # Samples: 7K of event 'anon group { ref-cycles, cycles }'
          # Event count (approx.): 6876107743
          #
          #         Overhead  Command      Shared Object                      Symbol
          # ................  .......  .................  ..........................
              99.84%  99.76%  noploop  noploop            [.] main
               0.07%   0.00%  noploop  ld-2.15.so         [.] strcmp
               0.03%   0.00%  noploop  [kernel.kallsyms]  [k] timerqueue_del
               0.03%   0.03%  noploop  [kernel.kallsyms]  [k] sched_clock_cpu
               0.02%   0.00%  noploop  [kernel.kallsyms]  [k] account_user_time
               0.01%   0.00%  noploop  [kernel.kallsyms]  [k] __alloc_pages_nodemask
               0.00%   0.00%  noploop  [kernel.kallsyms]  [k] native_write_msr_safe
               0.00%   0.11%  noploop  [kernel.kallsyms]  [k] _raw_spin_lock
               0.00%   0.06%  noploop  [kernel.kallsyms]  [k] find_get_page
               0.00%   0.02%  noploop  [kernel.kallsyms]  [k] rcu_check_callbacks
               0.00%   0.02%  noploop  [kernel.kallsyms]  [k] __current_kernel_time
      
        As you can see the Overhead column now contains both of ref-cycles and
        cycles and header line shows group information also - 'anon group {
        ref-cycles, cycles }'.  The output is sorted by period of group leader
        first.
      
        If perf.data file doesn't contain group information, this --group
        option does nothing.  So if you want enable event group view by
        default you can set it in ~/.perfconfig file:
      
          $ cat ~/.perfconfig
          [report]
          group = true
      
        It can be overridden with command line if you want:
      
          $ perf report --no-group
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      9c4c5fd9
  4. 31 Jan, 2013 26 commits
  5. 30 Jan, 2013 8 commits