Now, syswide tracing, selected entries:

  # trace -e clone
  24417.203 ( 0.158 ms): bash/11323 clone(flags: CHILD_CLEARTID|CHILD_SETTID|0x11, child_stack: 0, parent_tidptr: 0, child_tidptr: 0x7f0778e5c9d0, tls: 0x7f0778e5c700) = 11325 (bash)
          ? (     ?   ): bash/11325  ... [continued]: clone()) = 0
  24419.355 ( 0.093 ms): bash/10586 clone(flags: CHILD_CLEARTID|CHILD_SETTID|0x11, child_stack: 0, parent_tidptr: 0, child_tidptr: 0x7f0778e5c9d0, tls: 0x7f0778e5c700) = 11326 (bash)
          ? (     ?   ): bash/11326  ... [continued]: clone()) = 0
  24419.744 ( 0.102 ms): bash/11326 clone(flags: CHILD_CLEARTID|CHILD_SETTID|0x11, child_stack: 0, parent_tidptr: 0, child_tidptr: 0x7f0778e5c9d0, tls: 0x7f0778e5c700) = 11327 (bash)
          ? (     ?   ): bash/11327  ... [continued]: clone()) = 0
  24420.138 ( 0.105 ms): bash/11327 clone(flags: CHILD_CLEARTID|CHILD_SETTID|0x11, child_stack: 0, parent_tidptr: 0, child_tidptr: 0x7f0778e5c9d0, tls: 0x7f0778e5c700) = 11328 (bash)
          ? (     ?   ): bash/11328  ... [continued]: clone()) = 0
  35747.722 ( 0.044 ms): gpg-agent/18087 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ff0755f6ff0, parent_tidptr: 0x7ff0755f79d0, child_tidptr: 0x7ff0755f79d0, tls: 0x7ff0755f7700) = 11329 (gpg-agent)
          ? (     ?   ): gpg-agent/11329  ... [continued]: clone()) = 0
  35748.359 ( 0.022 ms): gpg-agent/18087 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ff075df7ff0, parent_tidptr: 0x7ff075df89d0, child_tidptr: 0x7ff075df89d0, tls: 0x7ff075df8700) = 11330 (gpg-agent)
          ? (     ?   ): gpg-agent/11330  ... [continued]: clone()) = 0
  35781.422 ( 0.452 ms): NetworkManager/1112 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7f2f1fffedb0, parent_tidptr: 0x7f2f1ffff9d0, child_tidptr: 0x7f2f1ffff9d0, tls: 0x7f2f1ffff700) = 11331 (NetworkManager)
          ? (     ?   ): NetworkManager/11331  ... [continued]: clone()) = 0

Need to improve the formatting of the second return, to the child, this
cset only focused on the argument formatting.

If we trace just one pid:

  # trace -e clone -p 19863
     0.349 ( 0.025 ms): Chrome_IOThrea/19863 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ffb84eaac70, parent_tidptr: 0x7ffb84eab9d0, child_tidptr: 0x7ffb84eab9d0, tls: 0x7ffb84eab700) = 11637 (Chrome_IOThread)
     0.392 ( 0.013 ms): Chrome_IOThrea/19863 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ffb664b8c70, parent_tidptr: 0x7ffb664b99d0, child_tidptr: 0x7ffb664b99d0, tls: 0x7ffb664b9700) = 11638 (Chrome_IOThread)
     0.573 ( 0.015 ms): Chrome_IOThrea/19863 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ffb6046cc70, parent_tidptr: 0x7ffb6046d9d0, child_tidptr: 0x7ffb6046d9d0, tls: 0x7ffb6046d700) = 11639 (Chrome_IOThread)
     0.617 ( 0.014 ms): Chrome_IOThrea/19863 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ffb730dcc70, parent_tidptr: 0x7ffb730dd9d0, child_tidptr: 0x7ffb730dd9d0, tls: 0x7ffb730dd700) = 11640 (Chrome_IOThread)
     4.350 ( 0.065 ms): Chrome_IOThrea/19863 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ffb720d9c70, parent_tidptr: 0x7ffb720da9d0, child_tidptr: 0x7ffb720da9d0, tls: 0x7ffb720da700) = 11642 (Chrome_IOThread)
     5.642 ( 0.079 ms): Chrome_IOThrea/19863 clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7ffb718d8c70, parent_tidptr: 0x7ffb718d99d0, child_tidptr: 0x7ffb718d99d0, tls: 0x7ffb718d9700) = 11643 (Chrome_IOThread)
^C#

We'll also have to fix the argument ordering in different arches,
probably having multiple syscall_fmt entries with each possible order
and then use perf_evsel__env_arch() (if dealing with a perf.data file)
or the current system info, for live sessions.

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-am068uyubgj83snepolwhbfe@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>