We should support this because it would allow easily to collect metrics
for different threads in applications.
Original patch from posted by Jin Yao in here [1].
1. Current output, for example:
root@skl:/tmp# perf stat --per-thread -p 21623
^C
Performance counter stats for process id '21623':
vmstat-21623 0.517479 task-clock (msec) # 0.000 CPUs utilized
vmstat-21623 1 context-switches
vmstat-21623 0 cpu-migrations
vmstat-21623 0 page-faults
vmstat-21623 461,306 cycles
vmstat-21623 630,724 instructions
vmstat-21623 136,265 branches
vmstat-21623 2,520 branch-misses
1.444020756 seconds time elapsed
root@skl:/tmp# perf stat --per-thread --metrics ipc -p 21623
^C
Performance counter stats for process id '21623':
vmstat-21623 631,185 inst_retired.any
vmstat-21623 605,893 cpu_clk_unhalted.thread
1.415679293 seconds time elapsed
2. With this patch, the result would be:
root@skl:/tmp# perf stat --per-thread -p 21623
^C
Performance counter stats for process id '21623':
vmstat-21623 0.533759 task-clock (msec) # 0.000 CPUs utilized
vmstat-21623 1 context-switches # 0.002 M/sec
vmstat-21623 0 cpu-migrations # 0.000 K/sec
vmstat-21623 0 page-faults # 0.000 K/sec
vmstat-21623 473,896 cycles # 0.888 GHz
vmstat-21623 631,072 instructions # 1.33 insn per cycle
vmstat-21623 136,307 branches # 255.372 M/sec
vmstat-21623 2,524 branch-misses # 1.85% of all branches
1.544862861 seconds time elapsed
root@skl:/tmp# perf stat --per-thread --metrics ipc -p 21623
^C
Performance counter stats for process id '21623':
vmstat-21623 1,259,104 inst_retired.any # 1.2 IPC
vmstat-21623 1,056,756 cpu_clk_unhalted.thread
2.040954502 seconds time elapsed
[1] https://marc.info/?l=linux-kernel&m=150777054620511&w=2
Originally-from: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-tr8ntktxmy4qc5769ajg5u6c@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
021b462a51