Like in stdio, it should print all events in a group together.

Committer notes:

Collect it:

  root@number:~# perf record -a -e '{cpu_core/mem-loads,ldlat=30/P,cpu_core/mem-stores/P}'
  ^C[ perf record: Woken up 8 times to write data ]
  [ perf record: Captured and wrote 4.980 MB perf.data (55825 samples) ]
  root@number:~#

Then do it in stdio:

  root@number:~# perf annotate --stdio --data-type

  Annotate type: 'union ' in /usr/lib64/libc.so.6 (1131 samples):
   event[0] = cpu_core/mem-loads,ldlat=30/P
   event[1] = cpu_core/mem-stores/P
  ============================================================================
           Percent     offset       size  field
    100.00  100.00          0         40  union    {
    100.00  100.00          0         40      struct __pthread_mutex_s    __data {
     48.61   23.46          0          4          int     __lock;
      0.00    0.48          4          4          unsigned int    __count;
      6.38   41.32          8          4          int     __owner;
      8.74   34.02         12          4          unsigned int    __nusers;
     35.66    0.26         16          4          int     __kind;
      0.61    0.45         20          2          short int       __spins;
      0.00    0.00         22          2          short int       __elision;
      0.00    0.00         24         16          __pthread_list_t        __list {
      0.00    0.00         24          8              struct __pthread_internal_list*     __prev;
      0.00    0.00         32          8              struct __pthread_internal_list*     __next;
                                                  };
                                              };
      0.00    0.00          0          0      char*       __size;
     48.61   23.94          0          8      long int    __align;
                                          };

Now with TUI before this patch:

  root@number:~# perf annotate --tui --data-type
  Annotate type: 'union ' (790 samples)
      Percent     Offset       Size  Field
       100.00          0         40  union  {
       100.00          0         40      struct __pthread_mutex_s __data {
        48.61          0          4          int  __lock;
         0.00          4          4          unsigned int __count;
         6.38          8          4          int  __owner;
         8.74         12          4          unsigned int __nusers;
        35.66         16          4          int  __kind;
         0.61         20          2          short int    __spins;
         0.00         22          2          short int    __elision;
         0.00         24         16          __pthread_list_t     __list {
         0.00         24          8              struct __pthread_internal_list*  __prev;
         0.00         32          8              struct __pthread_internal_list*  __next;

         0.00          0          0      char*    __size;
        48.61          0          8      long int __align;
                                     };

And now after this patch:

Annotate type: 'union ' (790 samples)
               Percent     Offset       Size  Field
     100.00     100.00          0         40  union  {
     100.00     100.00          0         40      struct __pthread_mutex_s      __data {
      48.61      23.46          0          4          int       __lock;
       0.00       0.48          4          4          unsigned int      __count;
       6.38      41.32          8          4          int       __owner;
       8.74      34.02         12          4          unsigned int      __nusers;
      35.66       0.26         16          4          int       __kind;
       0.61       0.45         20          2          short int __spins;
       0.00       0.00         22          2          short int __elision;
       0.00       0.00         24         16          __pthread_list_t  __list {
       0.00       0.00         24          8              struct __pthread_internal_list*       __prev;
       0.00       0.00         32          8              struct __pthread_internal_list*       __next;
                                                      };
                                                  };
       0.00       0.00          0          0      char* __size;
      48.61      23.94          0          8      long int      __align;
                                              };

On a followup patch the --tui output should have this that is present in
--stdio:

  And the --stdio has all the missing info in TUI:

    Annotate type: 'union ' in /usr/lib64/libc.so.6 (1131 samples):
     event[0] = cpu_core/mem-loads,ldlat=30/P
     event[1] = cpu_core/mem-stores/P
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240411033256.2099646-6-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>