The test to check if the arg format had been read from the
syscall:sys_enter_name/format file was looking at the list of non-commom
fields, and if that is empty, it would think it had failed to read it,
because it doesn't exist, for instance, for the clone() syscall.

So instead before dumping the raw syscall args list check
IS_ERR(sc->tp_format), if that is true, then an attempt was made to read
the format file and failed, in which case dump the raw arg list values.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ls7pmdqb2xy9339vdburwvnk@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

That field is only updated when we use the "sched:sched_stat_runtime"
tracepoint, and that is only done so far when we use the '--stat' command line
option, without it we get just zeros, confusing the users:

Without this patch:

  # trace -a -s sleep 1
  <SNIP>
   qemu-system-x86 (9931), 468 events, 9.6%, 0.000 msec

     syscall     calls    total       min       avg       max      stddev
                          (msec)    (msec)    (msec)    (msec)        (%)
     ---------- ------ --------- --------- --------- ---------     ------
     ppoll          98   982.374     0.000    10.024    29.983     12.65%
     write          34     0.401     0.005     0.012     0.027      5.49%
     ioctl         102     0.347     0.002     0.003     0.007      3.08%

   firefox (10871), 1856 events, 38.2%, 0.000 msec

                          (msec)    (msec)    (msec)    (msec)        (%)
     ---------- ------ --------- --------- --------- ---------     ------
     poll          395   934.873     0.000     2.367    17.120     11.51%
     recvmsg       395     0.988     0.001     0.003     0.021      4.20%
     read          106     0.460     0.002     0.004     0.007      3.17%
     futex          24     0.108     0.001     0.004     0.010     10.05%
     mmap            2     0.041     0.016     0.021     0.026     23.92%
     write           6     0.027     0.004     0.004     0.005      2.52%

After this patch that ', 0.000 msecs' gets suppressed when --stat is not
in use.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-p7emqrsw7900tdkg43v9l1e1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

  # trace -a -s sleep 1
  <SNIP>
   Xorg (1965), 788 events, 19.0%, 0.000 msec

     syscall            calls    total       min       avg       max      stddev
                                 (msec)    (msec)    (msec)    (msec)        (%)
     --------------- -------- --------- --------- --------- ---------     ------
     select                89   731.038     0.000     8.214   175.218     36.71%
     ioctl                 22     0.661     0.010     0.030     0.072     10.43%
     writev                42     0.253     0.002     0.006     0.011      5.94%
     recvmsg               60     0.185     0.001     0.003     0.009      5.90%
     setitimer             60     0.127     0.001     0.002     0.006      6.14%
     read                  52     0.102     0.001     0.002     0.005      8.55%
     rt_sigprocmask        45     0.092     0.001     0.002     0.023     23.65%
     poll                  12     0.021     0.001     0.002     0.003      7.21%
     epoll_wait            12     0.019     0.001     0.002     0.002      2.71%

   firefox (10871), 1080 events, 26.1%, 0.000 msec

     syscall            calls    total       min       avg       max      stddev
                                 (msec)    (msec)    (msec)    (msec)        (%)
     --------------- -------- --------- --------- --------- ---------     ------
     poll                 240   979.562     0.000     4.082    17.132     11.33%
     recvmsg              240     0.532     0.001     0.002     0.007      3.69%
     read                  60     0.303     0.003     0.005     0.029      8.50%
Suggested-by: NMilian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-52kdkuyxihq0kvc0n2aalhay@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

  # trace -a -s sleep 1 |& grep events | tail
   gmain (1733), 34 events, 1.0%, 0.000 msec
   hexchat (9765), 46 events, 1.4%, 0.000 msec
   ssh (11109), 80 events, 2.4%, 0.000 msec
   sleep (32631), 81 events, 2.4%, 0.000 msec
   qemu-system-x86 (10021), 272 events, 8.2%, 0.000 msec
   Xorg (1965), 322 events, 9.7%, 0.000 msec
   SoftwareVsyncTh (10922), 366 events, 11.1%, 0.000 msec
   gnome-shell (2231), 446 events, 13.5%, 0.000 msec
   qemu-system-x86 (9931), 468 events, 14.1%, 0.000 msec
   firefox (10871), 1098 events, 33.2%, 0.000 msec
  [root@jouet ~]#
Suggested-by: NMilian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ye4cnprhfeiq32ar4lt60dqs@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the size of builtin-trace.c.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-11zxg3qitk6bw2x30135k9z4@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Leave it alone so that it ends up assigned to SCA_PID via its type,
'pid_t', that will look up the pid on the machine thread rb_tree and
possibly find its COMM.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-r7dujgmhtxxfajuunpt1bkuo@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the size of builtin-trace.c.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-8r3gmymyn3r0ynt4yuzspp9g@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To check deeply nested page fault callchains.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wuji34xx003kr88nmqt6jkgf@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-shj0fazntmskhjild5i6x73l@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Forgot about page faults, a software event, when adding support for callchains,
fix it:

  # trace --no-syscalls --pf maj --call dwarf
     0.000 ( 0.000 ms): Xorg/2068 majfault [sfbSegment1+0x0] => /usr/lib64/xorg/modules/drivers/intel_drv.so@0x11b490 (x.)
                                       sfbSegment1+0x0 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       fbPolySegment32+0x361 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       sna_poly_segment+0x743 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       damagePolySegment+0x77 (/usr/libexec/Xorg)
                                       ProcPolySegment+0xe7 (/usr/libexec/Xorg)
                                       Dispatch+0x25f (/usr/libexec/Xorg)
                                       dix_main+0x3c3 (/usr/libexec/Xorg)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       _start+0x29 (/usr/libexec/Xorg)
     0.257 ( 0.000 ms): Xorg/2068 majfault [miZeroClipLine+0x0] => /usr/libexec/Xorg@0x18e830 (x.)
                                       miZeroClipLine+0x0 (/usr/libexec/Xorg)
                                       _fbSegment+0x2c0 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       sfbSegment1+0x67 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       fbPolySegment32+0x361 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       sna_poly_segment+0x743 (/usr/lib64/xorg/modules/drivers/intel_drv.so)
                                       damagePolySegment+0x77 (/usr/libexec/Xorg)
                                       ProcPolySegment+0xe7 (/usr/libexec/Xorg)
                                       Dispatch+0x25f (/usr/libexec/Xorg)
                                       dix_main+0x3c3 (/usr/libexec/Xorg)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       _start+0x29 (/usr/libexec/Xorg)
^C#

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-8h6ssirw5z15qyhy2lwd6f89@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Prep work for next patches, where we'll need access to the created
evsels, to possibly configure callchains.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2pcgsgnkgellhlcao4aub8tu@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We have callchain_param.enabled for that.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-silwqjc2t25ls42dsvg28pp5@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The variable is initialized and then conditionally set to a different
value, but not used when DWARF unwinding is not available, bummer, write
1000 times: "Run make -C tools/perf build-test"...

  builtin-trace.c: In function ‘cmd_trace’:
  builtin-trace.c:3112:6: error: variable ‘max_stack_user_set’ set but not
  used [-Werror=unused-but-set-variable]
    bool max_stack_user_set = true;
        ^
  cc1: all warnings being treated as err

Fix it by marking it as __maybe_unused.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 05614993 ("perf trace: Make --(min,max}-stack imply "--call-graph dwarf"")
Link: http://lkml.kernel.org/n/tip-85r40c5hhv6jnmph77l1hgsr@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the chances we'll overflow the mmap buffer, manual fine tuning
trumps this.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wxygbxmp1v9mng1ea28wet02@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If one uses:

  # perf trace --min-stack 16

Then it implicitly means that callgraphs should be enabled, and the best
option in terms of widespread availability is "dwarf".

Further work needed to choose a better alternative, LBR, in capable
systems.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-xtjmnpkyk42npekxz3kynzmx@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Counterpart to --max-stack, to help focusing on deeply nested calls. Can
be combined with --duration, etc.

E.g.:

  System wide syscall tracing looking for call stacks longer than 66:

  # trace --mmap-pages 32768 --filter-pid 2711 --call-graph dwarf,16384 --min-stack 66

  Or more compactly:

  # trace -m 32768 --filt 2711 --call dwarf,16384 --min-st 66
   363.027 ( 0.002 ms): gnome-shell/2287 poll(ufds: 0x7ffc5ea24230, nfds: 1, timeout_msecs: 4294967295         ) = 1
                                       [0xf6fdd] (/usr/lib64/libc-2.22.so)
                                       _xcb_conn_wait+0x92 (/usr/lib64/libxcb.so.1.1.0)
                                       _xcb_out_send+0x4d (/usr/lib64/libxcb.so.1.1.0)
                                       xcb_writev+0x45 (/usr/lib64/libxcb.so.1.1.0)
                                       _XSend+0x19e (/usr/lib64/libX11.so.6.3.0)
                                       _XReply+0x82 (/usr/lib64/libX11.so.6.3.0)
                                       XSync+0x4d (/usr/lib64/libX11.so.6.3.0)
                                       dri3_bind_tex_image+0x42 (/usr/lib64/libGL.so.1.2.0)
                                       _cogl_winsys_texture_pixmap_x11_update+0x117 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_texture_pixmap_x11_update+0x67 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_texture_pixmap_x11_pre_paint+0x13 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_pipeline_layer_pre_paint+0x5e (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_rectangles_validate_layer_cb+0x1b (/usr/lib64/libcogl.so.20.4.1)
                                       cogl_pipeline_foreach_layer+0xbe (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_framebuffer_draw_multitextured_rectangles+0x77 (/usr/lib64/libcogl.so.20.4.1)
                                       cogl_framebuffer_draw_multitextured_rectangle+0x51 (/usr/lib64/libcogl.so.20.4.1)
                                       paint_clipped_rectangle+0xb6 (/usr/lib64/libmutter.so.0.0.0)
                                       meta_shaped_texture_paint+0x3e3 (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_window_actor_paint+0x14b (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_window_group_paint+0x19f (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       [0x3d970] (/usr/lib64/gnome-shell/libgnome-shell.so)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_stage_paint+0x3a (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_stage_paint+0x45 (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0x164 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _clutter_stage_do_paint+0x17b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_stage_cogl_redraw+0x496 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _clutter_stage_do_update+0x117 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_clock_dispatch+0x169 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       g_main_context_dispatch+0x15a (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       g_main_context_iterate.isra.29+0x1e0 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       g_main_loop_run+0xc2 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       meta_run+0x2c (/usr/lib64/libmutter.so.0.0.0)
                                       main+0x3f7 (/usr/bin/gnome-shell)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       [0x2909] (/usr/bin/gnome-shell)
   363.038 ( 0.006 ms): gnome-shell/2287 writev(fd: 5<socket:[32540]>, vec: 0x7ffc5ea243a0, vlen: 3            ) = 4
                                       __GI___writev+0x2d (/usr/lib64/libc-2.22.so)
                                       _xcb_conn_wait+0x359 (/usr/lib64/libxcb.so.1.1.0)
                                       _xcb_out_send+0x4d (/usr/lib64/libxcb.so.1.1.0)
                                       xcb_writev+0x45 (/usr/lib64/libxcb.so.1.1.0)
                                       _XSend+0x19e (/usr/lib64/libX11.so.6.3.0)
                                       _XReply+0x82 (/usr/lib64/libX11.so.6.3.0)
                                       XSync+0x4d (/usr/lib64/libX11.so.6.3.0)
                                       dri3_bind_tex_image+0x42 (/usr/lib64/libGL.so.1.2.0)
                                       _cogl_winsys_texture_pixmap_x11_update+0x117 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_texture_pixmap_x11_update+0x67 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_texture_pixmap_x11_pre_paint+0x13 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_pipeline_layer_pre_paint+0x5e (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_rectangles_validate_layer_cb+0x1b (/usr/lib64/libcogl.so.20.4.1)
                                       cogl_pipeline_foreach_layer+0xbe (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_framebuffer_draw_multitextured_rectangles+0x77 (/usr/lib64/libcogl.so.20.4.1)
                                       cogl_framebuffer_draw_multitextured_rectangle+0x51 (/usr/lib64/libcogl.so.20.4.1)
                                       paint_clipped_rectangle+0xb6 (/usr/lib64/libmutter.so.0.0.0)
                                       meta_shaped_texture_paint+0x3e3 (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_window_actor_paint+0x14b (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_window_group_paint+0x19f (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       [0x3d970] (/usr/lib64/gnome-shell/libgnome-shell.so)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_stage_paint+0x3a (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_stage_paint+0x45 (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0x164 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _clutter_stage_do_paint+0x17b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_stage_cogl_redraw+0x496 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _clutter_stage_do_update+0x117 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_clock_dispatch+0x169 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       g_main_context_dispatch+0x15a (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       g_main_context_iterate.isra.29+0x1e0 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       g_main_loop_run+0xc2 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       meta_run+0x2c (/usr/lib64/libmutter.so.0.0.0)
                                       main+0x3f7 (/usr/bin/gnome-shell)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       [0x2909] (/usr/bin/gnome-shell)
   363.086 ( 0.042 ms): gnome-shell/2287 poll(ufds: 0x7ffc5ea24250, nfds: 1, timeout_msecs: 4294967295         ) = 1
                                       [0xf6fdd] (/usr/lib64/libc-2.22.so)
                                       _xcb_conn_wait+0x92 (/usr/lib64/libxcb.so.1.1.0)
                                       wait_for_reply+0xb7 (/usr/lib64/libxcb.so.1.1.0)
                                       xcb_wait_for_reply+0x61 (/usr/lib64/libxcb.so.1.1.0)
                                       _XReply+0x127 (/usr/lib64/libX11.so.6.3.0)
                                       XSync+0x4d (/usr/lib64/libX11.so.6.3.0)
                                       dri3_bind_tex_image+0x42 (/usr/lib64/libGL.so.1.2.0)
                                       _cogl_winsys_texture_pixmap_x11_update+0x117 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_texture_pixmap_x11_update+0x67 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_texture_pixmap_x11_pre_paint+0x13 (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_pipeline_layer_pre_paint+0x5e (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_rectangles_validate_layer_cb+0x1b (/usr/lib64/libcogl.so.20.4.1)
                                       cogl_pipeline_foreach_layer+0xbe (/usr/lib64/libcogl.so.20.4.1)
                                       _cogl_framebuffer_draw_multitextured_rectangles+0x77 (/usr/lib64/libcogl.so.20.4.1)
                                       cogl_framebuffer_draw_multitextured_rectangle+0x51 (/usr/lib64/libcogl.so.20.4.1)
                                       paint_clipped_rectangle+0xb6 (/usr/lib64/libmutter.so.0.0.0)
                                       meta_shaped_texture_paint+0x3e3 (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_window_actor_paint+0x14b (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_real_paint+0x20 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_window_group_paint+0x19f (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       [0x3d970] (/usr/lib64/gnome-shell/libgnome-shell.so)
                                       _g_closure_invoke_va+0xb2 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_stage_paint+0x3a (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       meta_stage_paint+0x45 (/usr/lib64/libmutter.so.0.0.0)
                                       _g_closure_invoke_va+0x164 (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit_valist+0xc0d (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       g_signal_emit+0x8f (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       clutter_actor_continue_paint+0x2bb (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_actor_paint.part.41+0x47b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _clutter_stage_do_paint+0x17b (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_stage_cogl_redraw+0x496 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       _clutter_stage_do_update+0x117 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       clutter_clock_dispatch+0x169 (/usr/lib64/libclutter-1.0.so.0.2400.2)
                                       g_main_context_dispatch+0x15a (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       g_main_context_iterate.isra.29+0x1e0 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       g_main_loop_run+0xc2 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                       meta_run+0x2c (/usr/lib64/libmutter.so.0.0.0)
                                       main+0x3f7 (/usr/bin/gnome-shell)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       [0x2909] (/usr/bin/gnome-shell)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-jncuxju9fibq2rl6olhqwjw6@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

With multiple threads, e.g. a system wide trace session, and one syscall is
midway in a thread and another thread starts another syscall we must print the
start of the interrupted syscall followed by ..., but that can't be done that
way when we use the --duration filter, as we have to wait for the syscall exit
to calculate the duration and decide if it should be filtered, so we have to
disable the interrupted logic and only print at syscall exit, duh.

Before:

  # trace --duration 100
  <SNIP>
   9.248 (0.023 ms): gnome-shell/2287 poll(ufds: 0x7ffc5ea26580, nfds: 1, timeout_msecs: 4294967295) ...
   9.296 (0.001 ms): gnome-shell/2287 recvmsg(fd: 11<socket:[35818]>, msg: 0x7ffc5ea264a0          ) ...
   9.311 (0.008 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                         ) ...
   9.859 (0.023 ms): gnome-shell/2287 poll(ufds: 0x7ffc5ea24250, nfds: 1, timeout_msecs: 4294967295) ...
   9.942 (0.051 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                         ) ...
  10.467 (0.003 ms): gnome-shell/2287 poll(ufds: 0x55e623431220, nfds: 50, timeout_msecs: 4294967295) ...
  11.136 (0.382 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                         ) ...
  11.223 (0.023 ms): SoftwareVsyncT/24369 futex(uaddr: 0x7f5ec5df8c14, op: WAIT_BITSET|PRIV, val: 1, utime: 0x7f5ec5df8b68, val3: 4294967295) ...
  16.865 (5.501 ms): firefox/24321 poll(ufds: 0x7f5ec388b460, nfds: 6, timeout_msecs: 4294967295   ) ...
  22.571 (0.006 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                         ) ...
  26.793 (4.063 ms): gnome-shell/2287 poll(ufds: 0x55e623431220, nfds: 50, timeout_msecs: 4294967295) ...
  26.917 (0.080 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                         ) ...
  27.291 (0.355 ms): qemu-system-x8/10065 ppoll(ufds: 0x55c98b39e400, nfds: 72, tsp: 0x7fffe4e4fe60, sigsetsize: 8) ...
  27.336 (0.012 ms): SoftwareVsyncT/24369 futex(uaddr: 0x7f5ec5df8c14, op: WAIT_BITSET|PRIV, val: 1, utime: 0x7f5ec5df8b68, val3: 4294967295) ...
  33.370 (5.958 ms): firefox/24321 poll(ufds: 0x7f5ec388b460, nfds: 6, timeout_msecs: 4294967295) ...
  33.866 (0.021 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                      ) ...
  35.762 (1.611 ms): gnome-shell/2287 poll(ufds: 0x55e623431220, nfds: 50, timeout_msecs: 8     ) ...
  38.765 (2.910 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                      ) ...

After:

  # trace --duration 100

  238.292 (153.226 ms): hexchat/2786 poll(ufds: 0x559ea372f370, nfds: 6, timeout_msecs: 153) = 0 Timeout
  249.634 (199.433 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x7ffdcbb63610        ) = 1
  385.583 (147.257 ms): hexchat/2786 poll(ufds: 0x559ea372f370, nfds: 6, timeout_msecs: 147) = 0 Timeout
  397.166 (110.779 ms): gnome-shell/2287 poll(ufds: 0x55e623431220, nfds: 50, timeout_msecs: 4294967295) = 1
  601.839 (132.066 ms): Xorg/2025 select(n: 512, inp: 0x83a8e0, tvp: 0x8316a0                          ) = 1
  602.445 (132.679 ms): gnome-shell/2287 poll(ufds: 0x55e623431220, nfds: 50, timeout_msecs: 4294967295) = 1
  686.122 (300.418 ms): hexchat/2786 poll(ufds: 0x559ea372f370, nfds: 6, timeout_msecs: 300) = 0 Timeout
  815.033 (184.641 ms): JS Helper/24352 futex(uaddr: 0x7f5ed98e584c, op: WAIT|PRIV, val: 1149859) = 0
  825.868 (195.469 ms): JS Helper/24351 futex(uaddr: 0x7f5ed98e584c, op: WAIT|PRIV, val: 1149860) = 0
  840.738 (210.335 ms): JS Helper/24350 futex(uaddr: 0x7f5ed98e584c, op: WAIT|PRIV, val: 1149861) = 0
  914.898 (158.692 ms): Compositor/24363 futex(uaddr: 0x7f5ec8dfebf4, op: WAIT|PRIV, val: 1) = 0
  915.199 (100.747 ms): Timer/24358 futex(uaddr: 0x7f5ed98e56cc, op: WAIT_BITSET|PRIV|CLKRT, val: 2545397, utime: 0x7f5ecdbfec30, val3: 4294967295) = 0
  986.639 (247.325 ms): hexchat/2786 poll(ufds: 0x559ea372f370, nfds: 6, timeout_msecs: 247) = 0 Timeout
  996.239 (500.591 ms): chrome/16237 poll(ufds: 0x3ecd739bd0, nfds: 5, timeout_msecs: 500) = 0 Timeout
 1042.890 (120.076 ms): Timer/24358 futex(uaddr: 0x7f5ed98e56cc, op: WAIT_BITSET|PRIV|CLKRT, val: 2545403, utime: 0x7f5ecdbfec30, val3: 4294967295) = -1 ETIMEDOUT Connection timed out

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d2nay6kjax5ro991c9kelvi5@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Similar to the one in the other tools (report, script, top).

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-lh7kk5a5t3erwxw31ah0cgar@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Not used at all, nuke it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-jf2w8ce8nl3wso3vuodg5jci@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This way the print routine merely does printing, not requiring access to
the resolving machinery, which helps disentangling the object files and
easing creating subsets with a limited functionality set.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2ti2jbra8fypdfawwwm3aee3@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce the size of builtin-trace.c.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ao91htwxdqwlwxr47gbluou1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To better organize all these beautifiers.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-zrw5zz7cnrs44o5osouyutvt@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To better organize all these beautifiers.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-zbr27mdy9ssdhux3ib2nfa7j@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Were the detached tarball (make perf-tar-src-pkg) build was failing because
those definitions aren't available in the system headers.

On RHEL7, for instance:

  builtin-trace.c: In function ‘syscall_arg__scnprintf_getrandom_flags’:
  builtin-trace.c:1113:14: error: ‘GRND_RANDOM’ undeclared (first use in this function)
    P_FLAG(RANDOM);
                ^
  builtin-trace.c:1114:14: error: ‘GRND_NONBLOCK’ undeclared (first use in this function)
    P_FLAG(NONBLOCK);
              ^

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-r8496g24a3kbqynvk6617b0e@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Were the detached tarball (make perf-tar-src-pkg) build was failing because
those definitions aren't available in the system headers.

On RHEL7, for instance:

  builtin-trace.c: In function ‘syscall_arg__scnprintf_seccomp_op’:
  builtin-trace.c:1069:7: error: ‘SECCOMP_SET_MODE_STRICT’ undeclared (first use in this function)
    P_SECCOMP_SET_MODE_OP(STRICT);
         ^
  builtin-trace.c:1069:7: note: each undeclared identifier is reported only once for each function it appears in
  builtin-trace.c:1070:7: error: ‘SECCOMP_SET_MODE_FILTER’ undeclared (first use in this function)
    P_SECCOMP_SET_MODE_OP(FILTER);
         ^
  builtin-trace.c: In function ‘syscall_arg__scnprintf_seccomp_flags’:
  builtin-trace.c:1091:14: error: ‘SECCOMP_FILTER_FLAG_TSYNC’ undeclared (first use in this function)
    P_FLAG(TSYNC);
                ^

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-4f8dzzwd7g6l5dzz693u7kul@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Doesn't make sense and was causing a segfault, fix it.

  # trace -e clone --no-syscalls --event sched:*exec firefox
  The -e option can't be used with --no-syscalls.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ccrahezikdk2uebptzr1eyyi@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Those were converted to be evsel methods long ago, move the
source to where it belongs.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-vja8rjmkw3gd5ungaeyb5s2j@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We already were able to ask for callchains for a specific event:

  # trace -e nanosleep --call dwarf --event sched:sched_switch/call-graph=fp/ usleep 1

This would enable tracing just the "nanosleep" syscall, with callchains
at syscall exit and would ask the kernel for frame pointer callchains to
be enabled for the "sched:sched_switch" tracepoint event, its just that
we were not resolving the callchain and printing it in 'perf trace', do
it:

  # trace -e nanosleep --call dwarf --event sched:sched_switch/call-graph=fp/ usleep 1
     0.425 ( 0.013 ms): usleep/6718 nanosleep(rqtp: 0x7ffcc1d16e20) ...
     0.425 (         ): sched:sched_switch:usleep:6718 [120] S ==> swapper/2:0 [120])
                                       __schedule+0xfe200402 ([kernel.kallsyms])
                                       schedule+0xfe200035 ([kernel.kallsyms])
                                       do_nanosleep+0xfe20006f ([kernel.kallsyms])
                                       hrtimer_nanosleep+0xfe2000dc ([kernel.kallsyms])
                                       sys_nanosleep+0xfe20007a ([kernel.kallsyms])
                                       do_syscall_64+0xfe200062 ([kernel.kallsyms])
                                       return_from_SYSCALL_64+0xfe200000 ([kernel.kallsyms])
                                       __nanosleep+0xffff008b8cbe2010 (/usr/lib64/libc-2.22.so)
     0.486 ( 0.073 ms): usleep/6718  ... [continued]: nanosleep()) = 0
                                       __nanosleep+0x10 (/usr/lib64/libc-2.22.so)
                                       usleep+0x34 (/usr/lib64/libc-2.22.so)
                                       main+0x1eb (/usr/bin/usleep)
                                       __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                       _start+0x29 (/usr/bin/usleep)
  #

Pretty compact, huh? DWARF callchains for raw_syscalls:sys_exit + frame
pointer callchains for a tracepoint, if your hardware supports LBR, go
wild with /call-graph=lbr/, guess the next step is to lift this from
'perf script':

  -F, --fields <str>    comma separated output fields prepend with 'type:'. Valid types: hw,sw,trace,raw.
                        Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,addr,symoff,period,iregs,brstack,brstacksym,flags

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2e7yiv5hqdm8jywlmfivvx2v@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Instead of having "[unknown]" as the name used for unresolved symbols,
use the address in the callchain, in hexadecimal form:

  28.801 ( 0.007 ms): qemu-system-x8/10065 ppoll(ufds: 0x55c98b39e400, nfds: 72, tsp: 0x7fffe4e4fe60, sigsetsize: 8) = 0 Timeout
                                     ppoll+0x91 (/usr/lib64/libc-2.22.so)
                                     [0x337309] (/usr/bin/qemu-system-x86_64)
                                     [0x336ab4] (/usr/bin/qemu-system-x86_64)
                                     main+0x1724 (/usr/bin/qemu-system-x86_64)
                                     __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                     [0xc59a9] (/usr/bin/qemu-system-x86_64)
  35.265 (14.805 ms): gnome-shell/2287  ... [continued]: poll()) = 1
                                     [0xf6fdd] (/usr/lib64/libc-2.22.so)
                                     g_main_context_iterate.isra.29+0x17c (/usr/lib64/libglib-2.0.so.0.4600.2)
                                     g_main_loop_run+0xc2 (/usr/lib64/libglib-2.0.so.0.4600.2)
                                     meta_run+0x2c (/usr/lib64/libmutter.so.0.0.0)
                                     main+0x3f7 (/usr/bin/gnome-shell)
                                     __libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
                                     [0x2909] (/usr/bin/gnome-shell)
Suggested-by: NMilian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We don't need the callchains at the syscall enter tracepoint, just when
finishing it at syscall exit, so reduce the overhead by asking for
callchains just at syscall exit.
Suggested-by: NMilian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Instead receive a callchain_param pointer to configure callchain
aspects, not doing so if NULL is passed.

This will allow fine grained control over which evsels in an evlist
gets callchains enabled.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2mupip6khc92mh5x4nw9to82@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The kernel parts are not that useful:

  # trace -m 512 -e nanosleep --call dwarf  usleep 1
     0.065 ( 0.065 ms): usleep/18732 nanosleep(rqtp: 0x7ffc4ee4e200) = 0
                                       syscall_slow_exit_work ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       __nanosleep (/usr/lib64/libc-2.22.so)
                                       usleep (/usr/lib64/libc-2.22.so)
                                       main (/usr/bin/usleep)
                                       __libc_start_main (/usr/lib64/libc-2.22.so)
                                       _start (/usr/bin/usleep)
  #

So lets just use perf_event_attr.exclude_callchain_kernel to avoid
collecting it in the ring buffer:

  # trace -m 512 -e nanosleep --call dwarf  usleep 1
     0.063 ( 0.063 ms): usleep/19212 nanosleep(rqtp: 0x7ffc3df10fb0) = 0
                                       __nanosleep (/usr/lib64/libc-2.22.so)
                                       usleep (/usr/lib64/libc-2.22.so)
                                       main (/usr/bin/usleep)
                                       __libc_start_main (/usr/lib64/libc-2.22.so)
                                       _start (/usr/bin/usleep)
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-qctu3gqhpim0dfbcp9d86c91@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

In 'perf trace' we're just interested in printing callchains, and we
don't want to use the symbol_conf.use_callchain, so move the callchain
part to a new method.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kcn3romzivcpxb3u75s9nz33@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As it receives a FILE, and its more than just the IP, which can even be
requested not to be printed.

For consistency with other similar methods in tools/perf/, name it as
perf_evsel__fprintf_sym() and make it return the number of bytes
printed, just like 'fprintf(3)'

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-84gawlqa3lhk63nf0t9vnqnn@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now, one can print the call chain for every encountered sys_exit event,
e.g.:

    $ perf trace -e nanosleep --call-graph dwarf path/to/ex_sleep
    1005.757 (1000.090 ms): ex_sleep/13167 nanosleep(...) = 0
                                             syscall_slow_exit_work ([kernel.kallsyms])
                                             syscall_return_slowpath ([kernel.kallsyms])
                                             int_ret_from_sys_call ([kernel.kallsyms])
                                             __nanosleep (/usr/lib/libc-2.23.so)
                                             [unknown] (/usr/lib/libQt5Core.so.5.6.0)
                                             QThread::sleep (/usr/lib/libQt5Core.so.5.6.0)
                                             main (path/to/ex_sleep)
                                             __libc_start_main (/usr/lib/libc-2.23.so)
                                             _start (path/to/ex_sleep)

Note that it is advised to increase the number of mmap pages to prevent
event losses when using this new feature. Often, adding `-m 10M` to the
`perf trace` invocation is enough.

This feature is also available in strace when built with libunwind via
`strace -k`. Performance wise, this solution is much better:

    $ time find path/to/linux &> /dev/null

    real    0m0.051s
    user    0m0.013s
    sys     0m0.037s

    $ time perf trace -m 800M --call-graph dwarf find path/to/linux &> /dev/null

    real    0m2.624s
    user    0m1.203s
    sys     0m1.333s

    $ time strace -k find path/to/linux  &> /dev/null

    real    0m35.398s
    user    0m10.403s
    sys     0m23.173s

Note that it is currently not possible to configure the print output.
Adding such a feature, similar to what is available in `perf script` via
its `--fields` knob can be added later on.
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
LPU-Reference: 1460115255-17648-1-git-send-email-milian.wolff@kdab.com
[ Split from a larger patch, do not print the IP, left align,
  remove dup call symbol__init(), added man page entry ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch allows cloning bpf-output event configuration among multiple
bpf scripts. If there exist a map named '__bpf_output__' and not
configured using 'map:__bpf_output__.event=', this patch clones the
configuration of another '__bpf_stdout__' map. For example, following
command:

  # perf trace --ev bpf-output/no-inherit,name=evt/ \
               --ev ./test_bpf_trace.c/map:__bpf_stdout__.event=evt/ \
               --ev ./test_bpf_trace2.c usleep 100000

equals to:

  # perf trace --ev bpf-output/no-inherit,name=evt/ \
               --ev ./test_bpf_trace.c/map:__bpf_stdout__.event=evt/  \
               --ev ./test_bpf_trace2.c/map:__bpf_stdout__.event=evt/ \
               usleep 100000
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Suggested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1460128045-97310-4-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We're using libaudit for doing name to id and id to syscall name
translations, but that makes 'perf trace' to have to wait for newer
libaudit versions supporting recently added syscalls, such as
"userfaultfd" at the time of this changeset.

We have all the information right there, in the kernel sources, so move
this code to a separate place, wrapped behind functions that will
progressively use the kernel source files to extract the syscall table
for use in 'perf trace'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-i38opd09ow25mmyrvfwnbvkj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When reading the syscall tracepoint /format file, look for arguments of type
"mode_t" and attach a beautifier:

  [root@jouet ~]# cat ~/bin/tp_with_fields_of_type
  #!/bin/bash
  grep -w $1 /sys/kernel/tracing/events/syscalls/*/format | sed -r 's%.*sys_enter_(.*)/format.*%\1%g' | paste -d, -s
  # tp_with_fields_of_type umode_t
  chmod,creat,fchmodat,fchmod,mkdirat,mkdir,mknodat,mknod,mq_open,openat,open
  #

Testing it:

  #define S_ISUID 0004000
  #define S_ISGID 0002000
  #define S_ISVTX 0001000
  #define S_IRWXU 0000700
  #define S_IRUSR 0000400
  #define S_IWUSR 0000200
  #define S_IXUSR 0000100

  #define S_IRWXG 0000070
  #define S_IRGRP 0000040
  #define S_IWGRP 0000020
  #define S_IXGRP 0000010

  #define S_IRWXO 0000007
  #define S_IROTH 0000004
  #define S_IWOTH 0000002
  #define S_IXOTH 0000001

  # for mode in 4000 2000 1000 700 400 200 100 70 40 20 10 7 4 2 1 ; do \
      echo -n $mode '->' ; trace --no-inherit -e chmod,fchmodat,fchmod chmod $mode x; \
    done
  4000 -> 0.338 ( 0.012 ms): fchmodat(dfd: CWD, filename: x, mode: ISUID) = 0
  2000 -> 0.438 ( 0.015 ms): fchmodat(dfd: CWD, filename: x, mode: ISGID) = 0
  1000 -> 0.677 ( 0.040 ms): fchmodat(dfd: CWD, filename: x, mode: ISVTX) = 0
   700 -> 0.394 ( 0.013 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXU) = 0
   400 -> 0.337 ( 0.010 ms): fchmodat(dfd: CWD, filename: x, mode: IRUSR) = 0
   200 -> 0.259 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IWUSR) = 0
   100 -> 0.249 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IXUSR) = 0
    70 -> 0.266 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXG) = 0
    40 -> 0.329 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IRGRP) = 0
    20 -> 0.250 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IWGRP) = 0
    10 -> 0.259 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IXGRP) = 0
     7 -> 0.249 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXO) = 0
     4 -> 0.278 ( 0.011 ms): fchmodat(dfd: CWD, filename: x, mode: IROTH) = 0
     2 -> 0.276 ( 0.009 ms): fchmodat(dfd: CWD, filename: x, mode: IWOTH) = 0
     1 -> 0.250 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: IXOTH) = 0
  #
  # trace --no-inherit -e chmod,fchmodat,fchmod chmod 7777 x
     0.258 ( 0.011 ms): fchmodat(dfd: CWD, filename: x, mode: IALLUGO) = 0
  # trace --no-inherit -e chmod,fchmodat,fchmod chmod 7770 x
     0.258 ( 0.008 ms): fchmodat(dfd: CWD, filename: x, mode: ISUID|ISGID|ISVTX|IRWXU|IRWXG) = 0
  # trace --no-inherit -e chmod,fchmodat,fchmod chmod 777 x
     0.293 ( 0.012 ms): fchmodat(dfd: CWD, filename: x, mode: IRWXUGO
  #

Now lets see if check by using the tracepoint for that specific syscall,
instead of raw_syscalls:sys_enter as 'trace' does for its strace fu:

  # trace --no-inherit --ev syscalls:sys_enter_fchmodat -e fchmodat chmod 666 x
     0.255 (         ): syscalls:sys_enter_fchmodat:dfd: 0xffffffffffffff9c, filename: 0x55db32a3f0f0, mode: 0x000001b6)
     0.268 ( 0.012 ms): fchmodat(dfd: CWD, filename: x, mode: IRUGO|IWUGO                     ) = 0
  #

Perfect, 0x1bc == 0666.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-18e8zfgbkj83xo87yoom43kd@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When reading the syscall tracepoint /format file, look for arguments
of type "pid_t" and attach the PID beautifier, that will do a lookup
on the threads it knows, i.e. the ones that came from PERF_RECORD_COMM
events and add the COMM after the pid in such args:

Excerpt of a system wide trace for syscalls with pid_t args:

  55602.977 ( 0.006 ms): bash/12122 setpgid(pid: 24347 (bash), pgid: 24347 (bash)) = 0
  55603.024 ( 0.004 ms): bash/24347 setpgid(pid: 24347 (bash), pgid: 24347 (bash)) = 0
  55691.527 (88.397 ms): bash/12122 wait4(upid: -1, stat_addr: 0x7ffe0cee1720, options: UNTRACED|CONTINUED) ...
  55692.479 ( 0.952 ms): git/24347 wait4(upid: 24368, stat_addr: 0x7ffe030d5724) ...
  55694.549 ( 2.070 ms): pre-commit/24368 wait4(upid: -1, stat_addr: 0x7ffc94f4fc10) = 24369 (pre-commit)
  55694.575 ( 0.002 ms): pre-commit/24368 wait4(upid: -1, stat_addr: 0x7ffc94f4f650, options: NOHANG) = -1 ECHILD No child processes
  55695.934 ( 0.010 ms): pre-commit/24368 wait4(upid: -1, stat_addr: 0x7ffc94f4f2d0, options: NOHANG) = 24370 (git)
  55695.937 ( 0.001 ms): pre-commit/24368 wait4(upid: -1, stat_addr: 0x7ffc94f4f2d0, options: NOHANG) = -1 ECHILD No child processes
  55717.963 ( 0.000 ms): pre-commit/24371  ... [continued]: wait4()) = 24372
  55717.978 (21.468 ms): :24371/24371 wait4(upid: -1, stat_addr: 0x7ffc94f4f230) ...
  55718.087 ( 0.109 ms): pre-commit/24371 wait4(upid: -1, stat_addr: 0x7ffc94f4f230) = 24373 (tr)
  55718.187 ( 0.096 ms): pre-commit/24371 wait4(upid: -1, stat_addr: 0x7ffc94f4f230) = 24374 (wc)
  55718.218 ( 0.002 ms): pre-commit/24371 wait4(upid: -1, stat_addr: 0x7ffc94f4eed0, options: NOHANG) = -1 ECHILD No child processes
  55718.367 ( 0.005 ms): pre-commit/24368 wait4(upid: -1, stat_addr: 0x7ffc94f4f1d0, options: NOHANG) = 24371 (pre-commit)
  55718.369 ( 0.001 ms): pre-commit/24368 wait4(upid: -1, stat_addr: 0x7ffc94f4f1d0, options: NOHANG) = -1 ECHILD No child processes
  55741.021 (49.494 ms): git/24347  ... [continued]: wait4()) = 24368 (pre-commit)
  74146.427 (18319.601 ms): git/24347 wait4(upid: 24375 (git), stat_addr: 0x7ffe030d6824) ...
  74149.036 ( 0.891 ms): bash/24391 wait4(upid: -1, stat_addr: 0x7ffe0cee0560) = 24393 (sed)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-75yl9hzjhb020iadc81gdj8t@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>