Currently all the -p option PID arguments tasks values
get aggregated and printed as single values.
Adding --per-tasks option to print values per task.
$ perf stat -e cycles,instructions --per-task -p 12451,16173
^C
Performance counter stats for process id '12451,16173':
TASK-12451 77,784 cycles
TASK-16173 64,809 cycles
TASK-12451 14,432 instructions
TASK-16173 14,452 instructions
3.854957122 seconds time elapsed
Also woks under interval mode:
$ ./perf stat -e cycles,instructions --per-task -p 16431,16173 -I 1000
# time task counts unit events
1.000085816 TASK-16173 0 cycles
1.000085816 TASK-16431 3,358,360,926 cycles
1.000085816 TASK-16173 0 instructions
1.000085816 TASK-16431 9,062,422,086 instructions
2.000212262 TASK-16173 65,386 cycles
2.000212262 TASK-16431 3,349,355,309 cycles
2.000212262 TASK-16173 12,151 instructions
2.000212262 TASK-16431 9,039,401,422 instructions
3.000333402 TASK-16173 62,797 cycles
3.000333402 TASK-16431 3,357,140,183 cycles
3.000333402 TASK-16173 12,208 instructions
3.000333402 TASK-16431 9,058,080,762 instructions
^C 3.375949851 TASK-16173 0 cycles
3.375949851 TASK-16431 1,264,764,804 cycles
3.375949851 TASK-16173 0 instructions
3.375949851 TASK-16431 3,414,532,317 instructions