We have already supported the '--total-cycles' option in previous patch.
It's also useful to show entries only above a threshold percent.

This patch enables '--percent-limit' for not showing entries
under that percent.

For example:

 perf report --total-cycles --stdio --percent-limit 1

 # To display the perf.data header info, please use --header/--header-only options.
 #
 #
 # Total Lost Samples: 0
 #
 # Samples: 2M of event 'cycles'
 # Event count (approx.): 2753248
 #
 # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                                              [Program Block Range]         Shared Object
 # ...............  ..............  ...........  ..........  .................................................................  ....................
 #
            26.04%            2.8M        0.40%          18                                             [div.c:42 -> div.c:39]                   div
            15.17%            1.2M        0.16%           7                                 [random_r.c:357 -> random_r.c:380]          libc-2.27.so
             5.11%          402.0K        0.04%           2                                             [div.c:27 -> div.c:28]                   div
             4.87%          381.6K        0.04%           2                                     [random.c:288 -> random.c:291]          libc-2.27.so
             4.53%          381.0K        0.04%           2                                             [div.c:40 -> div.c:40]                   div
             3.85%          300.9K        0.02%           1                                             [div.c:22 -> div.c:25]                   div
             3.08%          241.1K        0.02%           1                                           [rand.c:26 -> rand.c:27]          libc-2.27.so
             3.06%          240.0K        0.02%           1                                     [random.c:291 -> random.c:291]          libc-2.27.so
             2.78%          215.7K        0.02%           1                                     [random.c:298 -> random.c:298]          libc-2.27.so
             2.52%          198.3K        0.02%           1                                     [random.c:293 -> random.c:293]          libc-2.27.so
             2.36%          184.8K        0.02%           1                                           [rand.c:28 -> rand.c:28]          libc-2.27.so
             2.33%          180.5K        0.02%           1                                     [random.c:295 -> random.c:295]          libc-2.27.so
             2.28%          176.7K        0.02%           1                                     [random.c:295 -> random.c:295]          libc-2.27.so
             2.20%          168.8K        0.02%           1                                         [rand@plt+0 -> rand@plt+0]                   div
             1.98%          158.2K        0.02%           1                                 [random_r.c:388 -> random_r.c:388]          libc-2.27.so
             1.57%          123.3K        0.02%           1                                             [div.c:42 -> div.c:44]                   div
             1.44%          116.0K        0.42%          19                                 [random_r.c:357 -> random_r.c:394]          libc-2.27.so

Committer testing:

From second exapmple onwards slightly edited for brevity:

  # perf report --total-cycles --percent-limit 2 --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 6M of event 'cycles'
  # Event count (approx.): 6299936
  #
  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                                                   [Program Block Range]         Shared Object
  # ...............  ..............  ...........  ..........  ......................................................................  ....................
  #
              2.17%            1.7M        0.08%         607                                        [compiler.h:199 -> common.c:221]      [kernel.vmlinux]
  #
  # (Tip: Create an archive with symtabs to analyse on other machine: perf archive)
  #
  # perf report --total-cycles --percent-limit 1 --stdio
  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                                                   [Program Block Range]         Shared Object
              2.17%            1.7M        0.08%         607                                        [compiler.h:199 -> common.c:221]      [kernel.vmlinux]
              1.75%            1.3M        8.34%       65.5K    [memset-vec-unaligned-erms.S:147 -> memset-vec-unaligned-erms.S:151]          libc-2.29.so
  #
  # perf report --total-cycles --percent-limit 0.7 --stdio
  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                                                   [Program Block Range]         Shared Object
              2.17%            1.7M        0.08%         607                                        [compiler.h:199 -> common.c:221]      [kernel.vmlinux]
              1.75%            1.3M        8.34%       65.5K    [memset-vec-unaligned-erms.S:147 -> memset-vec-unaligned-erms.S:151]          libc-2.29.so
              0.72%          544.5K        0.03%         230                                      [entry_64.S:657 -> entry_64.S:662]      [kernel.vmlinux]
  #

-------------------------------------------

It only shows the entries which 'Sampled Cycles%' > 1%.

 v7:
 ---
 No functional change. Only fix the conflict issue because
 previous patches are changed.

 v6:
 ---
 No functional change. Only fix the conflict issue because
 previous patches are changed.

 v5:
 ---
 No functional change. Only fix the conflict issue because
 previous patches are changed.

 v4:
 ---
 No functional change. Only fix the build issue because
 previous patches are changed.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191107074719.26139-7-yao.jin@linux.intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>