To record an AUX area, the weak function auxtrace_record__init() must be
implemented.

Equally to decode an AUX area, the AUX area tracing type must be added
to the perf_event__process_auxtrace_info() function.

This patch makes those two changes plus hooks up default config for the
intel_pt PMU.  Also some brief documentation is provided for using the
tools with intel_pt.

Commiter note:

E.g:

  [root@perf4 ~]# dmesg
  451 [0.405807] Performance Events: PEBS fmt2+, 16-deep LBR, Broadwell events, full-width counters, Intel PMU driver.
  [root@perf4 ~]# perf --version
  perf version 4.1.g53874a
  [root@perf4 ~]#  perf record -e intel_pt//u -a sleep 10
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.383 MB perf.data ]
  [root@perf4 ~]# perf evlist
  intel_pt//u
  sched:sched_switch
  dummy:u
  [root@perf4 ~]# perf report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 0  of event 'intel_pt//u'
  # Event count (approx.): 0
  #
  # Overhead  Command  Shared Object  Symbol
  # ........  .......  .............  ......
  #

  # Samples: 393  of event 'sched:sched_switch'
  # Event count (approx.): 393
  #
  # Overhead  Command         Shared Object     Symbol
  # ........  ..............  ................  ..............
    49.62%  swapper         [kernel.vmlinux]  [k] __schedule
    10.69%  rcu_sched       [kernel.vmlinux]  [k] __schedule
     6.62%  rcuos/0         [kernel.vmlinux]  [k] __schedule
     5.60%  kworker/0:1     [kernel.vmlinux]  [k] __schedule
     3.56%  rcuos/3         [kernel.vmlinux]  [k] __schedule
     3.05%  kworker/u384:2  [kernel.vmlinux]  [k] __schedule
     2.54%  kworker/2:0     [kernel.vmlinux]  [k] __schedule
     2.54%  tuned           [kernel.vmlinux]  [k] __schedule
  <SNIP>
  # Samples: 0  of event 'dummy:u'
  # Event count (approx.): 0
  #
  # Overhead  Command  Shared Object  Symbol
  # ........  .......  .............  ......

  # Samples: 28  of event 'instructions:u'
  # Event count (approx.): 5030172
  #
  # Overhead  Command     Shared Object        Symbol
  # ........  ..........  ...................  ................................
  #
    21.43%  tuned       libpython2.7.so.1.0  [.] PyEval_EvalFrameEx
                 |
                 ---PyEval_EvalFrameEx
                    |
                    |--83.33%-- PyEval_EvalCodeEx
                    |          PyEval_EvalFrameEx
                    |          |
                    |          |--60.00%-- PyEval_EvalCodeEx
                    |          |          PyEval_EvalFrameEx
                    |          |          PyEval_EvalFrameEx
                    |          |
                    |           --40.00%-- PyEval_EvalFrameEx
                    |
                     --16.67%-- PyEval_EvalFrameEx
                               PyEval_EvalCodeEx
                               PyEval_EvalFrameEx
                               PyEval_EvalCodeEx
                               PyEval_EvalFrameEx
                               PyEval_EvalFrameEx

    14.29%  tuned       libpython2.7.so.1.0  [.] _PyType_Lookup
                 |
                 ---_PyType_Lookup
                    _PyObject_GenericGetAttrWithDict
                    PyEval_EvalFrameEx
                    PyEval_EvalCodeEx
                    PyEval_EvalFrameEx
                    PyEval_EvalCodeEx
                    PyEval_EvalFrameEx
                    |
                    |--75.00%-- PyEval_EvalFrameEx
                    |
                     --25.00%-- PyEval_EvalCodeEx
                               PyEval_EvalFrameEx
                               PyEval_EvalFrameEx

     3.57%  irqbalance  irqbalance           [.] 0x0000000000004038
            |
            ---0x4038
               0x4761
               0x4761
               0x4761
               0x49f1
               0x2295

     3.57%  irqbalance  libc-2.17.so         [.] __GI_____strtoull_l_internal
            |
            ---__GI_____strtoull_l_internal
               0x6f49
               0x229a

     3.57%  irqbalance  libc-2.17.so         [.] __strchrnul
            |
            ---__strchrnul
               vfprintf
               __vsprintf_chk
               __sprintf_chk
               0x2724
               0x4038
               0x2331

     3.57%  irqbalance  libc-2.17.so         [.] __strstr_sse42
            |
            ---__strstr_sse42
               0x71e0
               0x229f

  # And now to some userspace ftrace on uninstrumented binaries 8-) :
  # Hand edited to make it a bit more compact, replacing /home/acme/bin/perf
  # with /bin/perf:

  [root@perf4 ~]# perf script
     perf 8921 [3] 7.310889: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310889: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310889: 1 branches:u:       481694 perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310889: 1 branches:u:       481630 perf_evlist__enable (/bin/perf) => 4816d8 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310889: 1 branches:u:       4816de perf_evlist__enable (/bin/perf) => 48164f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310889: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310889: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.310889: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310889: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.310890: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310890: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310890: 1 branches:u:       481694 perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310890: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310890: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.310890: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310890: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.310893: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310893: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310893: 1 branches:u:       4816a8 perf_evlist__enable (/bin/perf) => 4815f8 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310893: 1 branches:u:       4815fe perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310893: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310893: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.310893: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310893: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.310956: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310956: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310956: 1 branches:u:       481694 perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310956: 1 branches:u:       481630 perf_evlist__enable (/bin/perf) => 4816d8 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310956: 1 branches:u:       4816de perf_evlist__enable (/bin/perf) => 48164f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310956: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310956: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.310956: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310956: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.310961: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310961: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310961: 1 branches:u:       481694 perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310961: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310961: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.310961: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310961: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.310968: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310968: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310968: 1 branches:u:       4816a8 perf_evlist__enable (/bin/perf) => 4815f8 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310968: 1 branches:u:       4815fe perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310968: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.310968: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.310968: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.310968: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.311040: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.311040: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311040: 1 branches:u:       481694 perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311040: 1 branches:u:       481630 perf_evlist__enable (/bin/perf) => 4816d8 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311040: 1 branches:u:       4816de perf_evlist__enable (/bin/perf) => 48164f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311040: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311040: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.311040: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.311040: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.311046: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.311046: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311046: 1 branches:u:       481694 perf_evlist__enable (/bin/perf) => 481614 perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311046: 1 branches:u:       481652 perf_evlist__enable (/bin/perf) => 48165f perf_evlist__enable (/bin/perf)
     perf 8921 [3] 7.311046: 1 branches:u:       481684 perf_evlist__enable (/bin/perf) => 41d250 ioctl@plt (/bin/perf)
     perf 8921 [3] 7.311046: 1 branches:u:       41d250 ioctl@plt (/bin/perf) => 7fcecadbf250 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.311046: 1 branches:u: 7fcecadbf255 __GI___ioctl (/usr/lib64/libc-2.17.so) => 0 [unknown] ([unknown])
     perf 8921 [3] 7.311050: 1 branches:u:            0 [unknown] ([unknown]) => 7fcecadbf257 __GI___ioctl (/usr/lib64/libc-2.17.so)
     perf 8921 [3] 7.311050: 1 branches:u: 7fcecadbf25f __GI___ioctl (/usr/lib64/libc-2.17.so) => 481689 perf_evlist__enable (/bin/perf)
:
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1437150840-31811-8-git-send-email-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>