perf metric: Reduce multiplexing with duration_time

It is common to use the same counters with and without duration_time.
The ID sharing code treats duration_time as if it were a hardware event
placed in the same group. This causes unnecessary multiplexing such as
in the following example where l3_cache_access isn't shared:

  $ perf stat -M l3 -a sleep 1

   Performance counter stats for 'system wide':

         3,117,007      l3_cache_miss         #    199.5 MB/s  l3_rd_bw
                                              #     43.6 %  l3_hits
                                              #     56.4 %  l3_miss                 (50.00%)
         5,526,447      l3_cache_access                                             (50.00%)
         5,392,435      l3_cache_access       # 5389191.2 access/s  l3_access_rate  (50.00%)
     1,000,601,901 ns   duration_time

       1.000601901 seconds time elapsed

Fix this by placing duration_time in all groups unless metric
sharing has been disabled on the command line:

  $ perf stat -M l3 -a sleep 1

   Performance counter stats for 'system wide':

         3,597,972      l3_cache_miss         #    230.3 MB/s  l3_rd_bw
                                              #     48.0 %  l3_hits
                                              #     52.0 %  l3_miss
         6,914,459      l3_cache_access       # 6909935.9 access/s  l3_access_rate
     1,000,654,579 ns   duration_time

       1.000654579 seconds time elapsed

  $ perf stat --metric-no-merge -M l3 -a sleep 1

   Performance counter stats for 'system wide':

         3,501,834      l3_cache_miss         #     53.5 %  l3_miss                (24.99%)
         6,548,173      l3_cache_access                                            (24.99%)
         3,417,622      l3_cache_miss         #     45.7 %  l3_hits                (25.04%)
         6,294,062      l3_cache_access                                            (25.04%)
         5,923,238      l3_cache_access       # 5919688.1 access/s  l3_access_rate (24.99%)
     1,000,599,683 ns   duration_time
         3,607,486      l3_cache_miss         #    230.9 MB/s  l3_rd_bw            (49.97%)

       1.000599683 seconds time elapsed

v2. Doesn't count duration_time in the metric_list_cmp function that
    sorts larger metrics first. Without this a metric with duration_time
    and an event is sorted the same as a metric with two events,
    possibly not allowing the first metric to share with the second.

Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Clarke <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions