perf: Add cputime events/metrics

hi,
so.. I failed to make work reliably the exclude_idle bit for cpu-clock event using the idle's process sum_exec_runtime as Peter outlined in his patch [1]. The time jumped up and down and I couldn't make it stable.

But I noticed we actually have IDLE stats (and many more) available for each CPU (enum cpu_usage_stat), we just can't reach them by perf yet.

This patchset adds 'cputime' perf software PMU, that provides CPUTIME_* stats via events that mirrors their names:

  # perf list | grep cputime
    cputime/guest/                                     [Kernel PMU event]
    cputime/guest_nice/                                [Kernel PMU event]
    cputime/idle/                                      [Kernel PMU event]
    cputime/iowait/                                    [Kernel PMU event]
    cputime/irq/                                       [Kernel PMU event]
    cputime/nice/                                      [Kernel PMU event]
    cputime/softirq/                                   [Kernel PMU event]
    cputime/steal/                                     [Kernel PMU event]
    cputime/system/                                    [Kernel PMU event]
    cputime/user/                                      [Kernel PMU event]

v2 changes:
- all of the support patches are already in
- new way of 'fixing' of idle counts when tick is disabled (patch 2)

Examples:

  # perf stat --top -I 1000
  #           time       Idle     System       User        Irq    Softirq    IO wait
       1.001692690     100.0%       0.0%       0.0%       0.7%       0.2%       0.0%
       2.002994039      98.9%       0.0%       0.0%       0.9%       0.2%       0.0%
       3.004164038      98.5%       0.2%       0.2%       0.9%       0.2%       0.0%
       4.005312773      98.9%       0.0%       0.0%       0.9%       0.2%       0.0%

  # perf stat --top-full -I 1000
  #           time       Idle     System       User        Irq    Softirq    IO wait      Guest Guest nice       Nice      Steal
       1.001750803     100.0%       0.0%       0.0%       0.7%       0.2%       0.0%       0.0%       0.0%       0.0%       0.0%
       2.003159490      99.0%       0.0%       0.0%       0.9%       0.2%       0.0%       0.0%       0.0%       0.0%       0.0%
       3.004358366      99.0%       0.0%       0.0%       0.9%       0.2%       0.0%       0.0%       0.0%       0.0%       0.0%
       4.005592436      98.9%       0.0%       0.0%       0.9%       0.2%       0.0%       0.0%       0.0%       0.0%       0.0%

  # perf stat -e cpu-clock,cputime/system/,cputime/user/,cputime/idle/ -a sleep 10

Performance counter stats for 'system wide':

       240070.828221      cpu-clock (msec)          #   23.999 CPUs utilized          
     208,910,979,120 ns   cputime/system/           #     87.0% System                
      20,589,603,359 ns   cputime/user/             #      8.6% User                  
       8,813,416,821 ns   cputime/idle/             #      3.7% Idle                  

        10.003261054 seconds time elapsed

  # perf stat -e cpu-clock,cputime/system/,cputime/user/ yes > /dev/null
  ^Cyes: Interrupt

Performance counter stats for 'yes':

         3483.824364      cpu-clock (msec)          #    1.000 CPUs utilized          
       2,460,117,205 ns   cputime/system/           #     70.6% System                
       1,018,360,669 ns   cputime/user/             #     29.2% User                  

         3.484554149 seconds time elapsed

         1.018525000 seconds user
         2.460515000 seconds sys

  # perf stat --top -I 1000 --interval-clear
  # perf stat --top -I 1000 --interval-clear --per-core
  # perf stat --top -I 1000 --interval-clear --per-socket
  # perf stat --top -I 1000 --interval-clear -A

It's also available in here:
git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
perf/fixes

thanks,
jirka

[1] https://marc.info/?l=linux-kernel&m=152397251027433&w=2
---
Jiri Olsa (3):
perf/cputime: Add cputime pmu
perf/cputime: Fix idle time on NO_HZ config perf stat: Add cputime metric support

 include/linux/perf_event.h             |   2 ++
 include/linux/tick.h                   |   1 +
 kernel/events/Makefile                 |   2 +-
 kernel/events/core.c                   |   1 +
 kernel/events/cputime.c                | 221 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/time/tick-sched.c               |  11 ++++++
 tools/perf/Documentation/perf-stat.txt |  65 +++++++++++++++++++++++++++++++++
 tools/perf/builtin-stat.c              |  47 ++++++++++++++++++++++++
 tools/perf/util/stat-shadow.c          |  72 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/stat.c                 |  10 ++++++
 tools/perf/util/stat.h                 |  10 ++++++
 11 files changed, 441 insertions(+), 1 deletion(-)
 create mode 100644 kernel/events/cputime.c