tree b8164ed1ea3e65aa866310d447a760f42350e08c
parent b65a7d372b1a55db6fb48a5b3c48941eb68716cb
author Jin Yao <yao.jin@linux.intel.com> 1573112837 +0800
committer Arnaldo Carvalho de Melo <acme@redhat.com> 1573132488 -0300

perf report: Sort by sampled cycles percent per block for stdio

It would be useful to support sorting for all blocks by the sampled
cycles percent per block. This is useful to concentrate on the globally
hottest blocks.

This patch implements a new option "--total-cycles" which sorts all
blocks by 'Sampled Cycles%'. The 'Sampled Cycles%' is the percent:

 percent = block sampled cycles aggregation / total sampled cycles

Note that, this patch only supports "--stdio" mode.

For example,

  # perf record -b ./div
  # perf report --total-cycles --stdio
  # 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
              0.25%          182.5K        0.02%           1                [random_r.c:388 -> random_r.c:391]       libc-2.27.so
              0.00%              48        1.07%          48        [x86_pmu_enable+284 -> x86_pmu_enable+298]  [kernel.kallsyms]
              0.00%              74        1.64%          74             [vm_mmap_pgoff+0 -> vm_mmap_pgoff+92]  [kernel.kallsyms]
              0.00%              73        1.62%          73                         [vm_mmap+0 -> vm_mmap+48]  [kernel.kallsyms]
              0.00%              63        0.69%          31                       [up_write+0 -> up_write+34]  [kernel.kallsyms]
              0.00%              13        0.29%          13      [setup_arg_pages+396 -> setup_arg_pages+413]  [kernel.kallsyms]
              0.00%               3        0.07%           3      [setup_arg_pages+418 -> setup_arg_pages+450]  [kernel.kallsyms]
              0.00%             616        6.84%         308   [security_mmap_file+0 -> security_mmap_file+72]  [kernel.kallsyms]
              0.00%              23        0.51%          23  [security_mmap_file+77 -> security_mmap_file+87]  [kernel.kallsyms]
              0.00%               4        0.02%           1                  [sched_clock+0 -> sched_clock+4]  [kernel.kallsyms]
              0.00%               4        0.02%           1                 [sched_clock+9 -> sched_clock+12]  [kernel.kallsyms]
              0.00%               1        0.02%           1                [rcu_nmi_exit+0 -> rcu_nmi_exit+9]  [kernel.kallsyms]

Committer testing:

This should provide material for hours of endless joy, both from looking
for suspicious things in the implementation of this patch, such as the
top one:

  # 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]

As well from things that look legit:

  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                          [Program Block Range]     Shared Object
              0.16%          123.0K        0.60%        4.7K   [nospec-branch.h:265 -> nospec-branch.h:278]  [kernel.vmlinux]

:-)

Very short system wide taken branches session:

  # perf record -h -b

   Usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -b, --branch-any      sample any taken branches

  #
  # perf record -b
  ^C[ perf record: Woken up 595 times to write data ]
  [ perf record: Captured and wrote 156.672 MB perf.data (196873 samples) ]

  #
  # perf evlist -v
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|BRANCH_STACK, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: ANY
  #
  # perf report --total-cycles --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]
              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]
              0.56%          541.8K        0.09%         672                                        [compiler.h:199 -> common.c:300]      [kernel.vmlinux]
              0.39%          293.2K        0.01%         104                                    [list_debug.c:43 -> list_debug.c:61]      [kernel.vmlinux]
              0.36%          278.6K        0.03%         272                                    [entry_64.S:1289 -> entry_64.S:1308]      [kernel.vmlinux]
              0.30%          260.8K        0.07%         564                              [clear_page_64.S:47 -> clear_page_64.S:50]      [kernel.vmlinux]
              0.28%          215.3K        0.05%         369                                            [traps.c:623 -> traps.c:628]      [kernel.vmlinux]
              0.23%          178.1K        0.04%         278                                      [entry_64.S:271 -> entry_64.S:275]      [kernel.vmlinux]
              0.20%          152.6K        0.09%         706                                      [paravirt.c:177 -> paravirt.c:179]      [kernel.vmlinux]
              0.20%          155.8K        0.05%         373                                      [entry_64.S:153 -> entry_64.S:175]      [kernel.vmlinux]
              0.18%          136.6K        0.03%         222                                                [msr.h:105 -> msr.h:166]      [kernel.vmlinux]
              0.16%          123.0K        0.60%        4.7K                            [nospec-branch.h:265 -> nospec-branch.h:278]      [kernel.vmlinux]
              0.16%          118.3K        0.01%          44                                      [entry_64.S:632 -> entry_64.S:657]      [kernel.vmlinux]
              0.14%          104.5K        0.00%          28                                          [rwsem.c:1541 -> rwsem.c:1544]      [kernel.vmlinux]
              0.13%           99.2K        0.01%          53                                      [spinlock.c:150 -> spinlock.c:152]      [kernel.vmlinux]
              0.13%           95.5K        0.00%          35                                              [swap.c:456 -> swap.c:471]      [kernel.vmlinux]
              0.12%           96.2K        0.05%         407                              [copy_user_64.S:175 -> copy_user_64.S:209]      [kernel.vmlinux]
              0.11%           85.9K        0.00%          31                                        [swap.c:400 -> page-flags.h:188]      [kernel.vmlinux]
              0.10%           73.0K        0.01%          52                                          [paravirt.h:763 -> list.h:131]      [kernel.vmlinux]
              0.07%           56.2K        0.03%         214                                      [filemap.c:1524 -> filemap.c:1557]      [kernel.vmlinux]
              0.07%           54.2K        0.02%         145                                        [memory.c:1032 -> memory.c:1049]      [kernel.vmlinux]
              0.07%           50.3K        0.00%          39                                            [mmzone.c:49 -> mmzone.c:69]      [kernel.vmlinux]
              0.06%           48.3K        0.01%          40                                   [paravirt.h:768 -> page_alloc.c:3304]      [kernel.vmlinux]
              0.06%           46.7K        0.02%         155                                        [memory.c:1032 -> memory.c:1056]      [kernel.vmlinux]
              0.06%           46.9K        0.01%         103                                              [swap.c:867 -> swap.c:902]      [kernel.vmlinux]
              0.06%           47.8K        0.00%          34                                    [entry_64.S:1201 -> entry_64.S:1202]      [kernel.vmlinux]

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

 v7:
 ---
 Use use_browser in report__browse_block_hists for supporting
 stdio and potential tui mode.

 v6:
 ---
 Create report__browse_block_hists in block-info.c (codes are
 moved from builtin-report.c). It's called from
 perf_evlist__tty_browse_hists.

 v5:
 ---
 1. Move all block functions to block-info.c

 2. Move the code of setting ms in block hist_entry to
    other patch.

 v4:
 ---
 1. Use new option '--total-cycles' to replace
    '-s total_cycles' in v3.

 2. Move block info collection out of block info
    printing.

 v3:
 ---
 1. Use common function block_info__process_sym to
    process the blocks per symbol.

 2. Remove the nasty hack for skipping calculation
    of column length

 3. Some minor cleanup

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/20191107074719.26139-6-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>