By default, perf sched map prints sched-in events for all the tasks
which may not be required all the time as it prints lot of symbols
and rows to the terminal.

With --task-name option, one could specify the specific task name
for which the map has to be shown. This would help in analyzing the
CPU usage patterns easier for that specific task. Since multiple
PID's might have the same task name, using task-name filter
would be more useful for debugging.

For other tasks, instead of printing the symbol, '-' is printed and
the same '.' is used to represent idle. '-' is used instead of symbol
for other tasks because it helps in clear visualization of task
of interest and secondly the symbol itself doesn't mean anything
because the sched-in of that symbol will not be printed(first sched-in
contains pid and the corresponding symbol).

When using the --task-name option, the sched-out time is represented
by a '*-'. Since not all task sched-in events are printed, the sched-out
time of the relevant task might be lost. This representation ensures
that the sched-out time of the interested task is not overlooked.

6.10.0-rc1
==========
*A0                              131040.639793 secs A0 => migration/0:19
*.                               131040.639801 secs .  => swapper:0
 .  *B0                          131040.639830 secs B0 => migration/1:24
 .  *.                           131040.639836 secs
 .   .  *C0                      131040.640108 secs C0 => migration/2:30
 .   .  *.                       131040.640163 secs
 .   .   .  *D0                  131040.640386 secs D0 => migration/3:36
 .   .   .  *.                   131040.640395 secs

6.10.0-rc1 + patch (--task-name wdavdaemon)
=============
 .  *A0  .   .   .   .   -   .   131040.641346 secs A0 => wdavdaemon:62509
 .   A0 *B0  .   .   .   -   .   131040.641378 secs B0 => wdavdaemon:62274
 -  *-   B0  .   .   .   -   .   131040.641379 secs
*C0  .   B0  .   .   .   .   .   131040.641572 secs C0 => wdavdaemon:62283
 C0  .   B0  .  *D0  .   .   .   131040.641572 secs D0 => wdavdaemon:62277
 C0  .   B0  .   D0  .  *E0  .   131040.641578 secs E0 => wdavdaemon:62270
*-   .   B0  .   D0  .   E0  .   131040.641581 secs
 .   .   B0  .   D0  .  *-   .   131040.641583 secs
Reviewed-and-tested-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
Cc: Chen Yu <yu.c.chen@intel.com>
Link: https://lore.kernel.org/r/20240707182716.22054-2-vineethr@linux.ibm.comSigned-off-by: Namhyung Kim <namhyung@kernel.org>