GitLab

Previously if '-e' is not specified in perf stat, some software events
and hardware events are added to evlist by default.

Before:

  # perf stat -a -- sleep 1

   Performance counter stats for 'system wide':

           24,044.40 msec cpu-clock                 #   23.946 CPUs utilized
                  99      context-switches          #    4.117 /sec
                  24      cpu-migrations            #    0.998 /sec
                   3      page-faults               #    0.125 /sec
           7,000,244      cycles                    #    0.000 GHz
           2,955,024      instructions              #    0.42  insn per cycle
             608,941      branches                  #   25.326 K/sec
              31,991      branch-misses             #    5.25% of all branches

         1.004106859 seconds time elapsed

Among the events, cycles, instructions, branches and branch-misses
are hardware events.

One hybrid platform, two hardware events are created for one
hardware event.

cpu_core/cycles/,
cpu_atom/cycles/,
cpu_core/instructions/,
cpu_atom/instructions/,
cpu_core/branches/,
cpu_atom/branches/,
cpu_core/branch-misses/,
cpu_atom/branch-misses/

These events would be added to evlist on hybrid platform.

Since parse_events() has been supported to create two hardware events
for one event on hybrid platform, so we just use parse_events(evlist,
"cycles,instructions,branches,branch-misses") to create the default
events and add them to evlist.

After:

  # perf stat -a -- sleep 1

   Performance counter stats for 'system wide':

           24,043.99 msec cpu-clock                 #   23.991 CPUs utilized
                 139      context-switches          #    5.781 /sec
                  25      cpu-migrations            #    1.040 /sec
                   6      page-faults               #    0.250 /sec
          10,381,751      cpu_core/cycles/          #  431.782 K/sec
           1,264,216      cpu_atom/cycles/          #   52.579 K/sec
           3,406,958      cpu_core/instructions/    #  141.697 K/sec
             414,588      cpu_atom/instructions/    #   17.243 K/sec
             705,149      cpu_core/branches/        #   29.327 K/sec
              82,358      cpu_atom/branches/        #    3.425 K/sec
              40,821      cpu_core/branch-misses/   #    1.698 K/sec
               9,086      cpu_atom/branch-misses/   #  377.891 /sec

         1.002228863 seconds time elapsed

We can see two events are created for one hardware event.

One TODO is, the shadow stats looks a bit different, now it's just
'M/sec'.

The perf_stat__update_shadow_stats and perf_stat__print_shadow_stats
need to be improved in future if we want to get the original shadow
stats.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210427070139.25256-15-yao.jin@linux.intel.com

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>