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perf report: Fix wrong LBR block sorting

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When '--total-cycles' is specified, it supports sorting for all blocks
by 'Sampled Cycles%'. This is useful to concentrate on the globally
hottest blocks.

'Sampled Cycles%' - block sampled cycles aggregation / total sampled cycles

But in current code, it doesn't use the cycles aggregation. Part of
'cycles' counting is possibly dropped for some overlap jumps. But for
identifying the hot block, we always need the full cycles.

  # perf record -b ./triad_loop
  # perf report --total-cycles --stdio

Before:

  #
  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                                          [Program Block Range]      Shared Object
  # ...............  ..............  ...........  ..........  .............................................................  .................
  #
              0.81%             793        4.32%         793                           [setup-vdso.h:34 -> setup-vdso.h:40]         ld-2.27.so
              0.49%             480        0.87%         160                    [native_write_msr+0 -> native_write_msr+16]  [kernel.kallsyms]
              0.48%             476        0.52%          95                      [native_read_msr+0 -> native_read_msr+29]  [kernel.kallsyms]
              0.31%             303        1.65%         303                              [nmi_restore+0 -> nmi_restore+37]  [kernel.kallsyms]
              0.26%             255        1.39%         255      [nohz_balance_exit_idle+75 -> nohz_balance_exit_idle+162]  [kernel.kallsyms]
              0.24%             234        1.28%         234                       [end_repeat_nmi+67 -> end_repeat_nmi+83]  [kernel.kallsyms]
              0.23%             227        1.24%         227            [__irqentry_text_end+96 -> __irqentry_text_end+126]  [kernel.kallsyms]
              0.20%             194        1.06%         194             [native_set_debugreg+52 -> native_set_debugreg+56]  [kernel.kallsyms]
              0.11%             106        0.14%          26                [native_sched_clock+0 -> native_sched_clock+98]  [kernel.kallsyms]
              0.10%              97        0.53%          97            [trigger_load_balance+0 -> trigger_load_balance+67]  [kernel.kallsyms]
              0.09%              85        0.46%          85             [get-dynamic-info.h:102 -> get-dynamic-info.h:111]         ld-2.27.so
  ...
              0.00%           92.7K        0.02%           4                           [triad_loop.c:64 -> triad_loop.c:65]         triad_loop

The hottest block '[triad_loop.c:64 -> triad_loop.c:65]' is not at
the top of output.

After:

  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                                           [Program Block Range]      Shared Object
  # ...............  ..............  ...........  ..........  ..............................................................  .................
  #
             94.35%           92.7K        0.02%           4                            [triad_loop.c:64 -> triad_loop.c:65]         triad_loop
              0.81%             793        4.32%         793                            [setup-vdso.h:34 -> setup-vdso.h:40]         ld-2.27.so
              0.49%             480        0.87%         160                     [native_write_msr+0 -> native_write_msr+16]  [kernel.kallsyms]
              0.48%             476        0.52%          95                       [native_read_msr+0 -> native_read_msr+29]  [kernel.kallsyms]
              0.31%             303        1.65%         303                               [nmi_restore+0 -> nmi_restore+37]  [kernel.kallsyms]
              0.26%             255        1.39%         255       [nohz_balance_exit_idle+75 -> nohz_balance_exit_idle+162]  [kernel.kallsyms]
              0.24%             234        1.28%         234                        [end_repeat_nmi+67 -> end_repeat_nmi+83]  [kernel.kallsyms]
              0.23%             227        1.24%         227             [__irqentry_text_end+96 -> __irqentry_text_end+126]  [kernel.kallsyms]
              0.20%             194        1.06%         194              [native_set_debugreg+52 -> native_set_debugreg+56]  [kernel.kallsyms]
              0.11%             106        0.14%          26                 [native_sched_clock+0 -> native_sched_clock+98]  [kernel.kallsyms]
              0.10%              97        0.53%          97             [trigger_load_balance+0 -> trigger_load_balance+67]  [kernel.kallsyms]
              0.09%              85        0.46%          85              [get-dynamic-info.h:102 -> get-dynamic-info.h:111]         ld-2.27.so
              0.08%              82        0.06%          11  [intel_pmu_drain_pebs_nhm+580 -> intel_pmu_drain_pebs_nhm+627]  [kernel.kallsyms]
              0.08%              77        0.42%          77                  [lru_add_drain_cpu+0 -> lru_add_drain_cpu+133]  [kernel.kallsyms]
              0.08%              74        0.10%          18                [handle_pmi_common+271 -> handle_pmi_common+310]  [kernel.kallsyms]
              0.08%              74        0.40%          74              [get-dynamic-info.h:131 -> get-dynamic-info.h:157]         ld-2.27.so
              0.07%              69        0.09%          17  [intel_pmu_drain_pebs_nhm+432 -> intel_pmu_drain_pebs_nhm+468]  [kernel.kallsyms]

Now the hottest block is reported at the top of output.

Fixes: b65a7d372b ("perf hist: Support block formats with compare/sort/display")
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210407024452.29988-1-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jin Yao 2021-04-07 10:44:52 +08:00 committed by Arnaldo Carvalho de Melo
parent 026334a3bb
commit f2013278ae
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
tools/perf/util/block-info.c
View File

@ -201,7 +201,7 @@ static int block_total_cycles_pct_entry(struct perf_hpp_fmt *fmt,
double ratio = 0.0;
if (block_fmt->total_cycles)
ratio = (double)bi->cycles / (double)block_fmt->total_cycles;
ratio = (double)bi->cycles_aggr / (double)block_fmt->total_cycles;
return color_pct(hpp, block_fmt->width, 100.0 * ratio);
}
@ -216,9 +216,9 @@ static int64_t block_total_cycles_pct_sort(struct perf_hpp_fmt *fmt,
double l, r;
if (block_fmt->total_cycles) {
l = ((double)bi_l->cycles /
l = ((double)bi_l->cycles_aggr /
(double)block_fmt->total_cycles) * 100000.0;
r = ((double)bi_r->cycles /
r = ((double)bi_r->cycles_aggr /
(double)block_fmt->total_cycles) * 100000.0;
return (int64_t)l - (int64_t)r;
}