Add NO_NMI_WATCHDOG metric constraint to Page_Walks_Utilization for Sky Lake
and Cascade Lake.
Committer testing:
On a Lenovo T480S, Intel(R) Core(TM) i7-8650U Kaby Lake, that looking at x86's
mapfile.csv file is a:
  $ grep -w skylake tools/perf/pmu-events/arch/x86/mapfile.csv
  GenuineIntel-6-[4589]E,v24,skylake,core
  $
So uses the constraint added in this patch in this file:
  tools/perf/pmu-events/arch/x86/skylake/skl-metrics.json
Before:
  # perf stat -a -M Page_Walks_Utilization sleep 2
   Performance counter stats for 'system wide':
       <not counted>      itlb_misses.walk_pending                                      (0.00%)
       <not counted>      dtlb_load_misses.walk_pending                                     (0.00%)
       <not counted>      dtlb_store_misses.walk_pending                                     (0.00%)
       <not counted>      ept.walk_pending                                              (0.00%)
       <not counted>      cycles                                                        (0.00%)
         2.
001750514 seconds time elapsed
  Some events weren't counted. Try disabling the NMI watchdog:
  	echo 0 > /proc/sys/kernel/nmi_watchdog
  	perf stat ...
  	echo 1 > /proc/sys/kernel/nmi_watchdog
  The events in group usually have to be from the same PMU. Try reorganizing the group.
  #
After:
  # perf stat -a -M Page_Walks_Utilization sleep 2
  Splitting metric group Page_Walks_Utilization into standalone metrics.
  Try disabling the NMI watchdog to comply NO_NMI_WATCHDOG metric constraint:
      echo 0 > /proc/sys/kernel/nmi_watchdog
      perf stat ...
      echo 1 > /proc/sys/kernel/nmi_watchdog
  ,
   Performance counter stats for 'system wide':
          36,883,102      itlb_misses.walk_pending  #      0.1 Page_Walks_Utilization   (79.99%)
         123,104,146      dtlb_load_misses.walk_pending                                     (80.02%)
          13,720,795      dtlb_store_misses.walk_pending                                     (79.99%)
                   0      ept.walk_pending                                              (79.99%)
       1,519,948,400      cycles                                                        (80.01%)
         2.
002170780 seconds time elapsed
  #
Before and after, if we disable the nmi_watchdog we get:
  # echo 0 > /proc/sys/kernel/nmi_watchdog
  # perf stat -a -M Page_Walks_Utilization sleep 2
   Performance counter stats for 'system wide':
          33,721,658      itlb_misses.walk_pending  #      0.1 Page_Walks_Utilization
          84,070,996      dtlb_load_misses.walk_pending
           9,816,071      dtlb_store_misses.walk_pending
                   0      ept.walk_pending
         704,920,899      cycles
         2.
002331670 seconds time elapsed
  #
  More information about the metric expressions:
  # perf stat -v -a -M Page_Walks_Utilization sleep 2
  Using CPUID GenuineIntel-6-8E-A
  metric expr ( itlb_misses.walk_pending + dtlb_load_misses.walk_pending + dtlb_store_misses.walk_pending + ept.walk_pending ) / ( 2 * cycles ) for Page_Walks_Utilization
  found event itlb_misses.walk_pending
  found event dtlb_load_misses.walk_pending
  found event dtlb_store_misses.walk_pending
  found event ept.walk_pending
  found event cycles
  adding {itlb_misses.walk_pending,dtlb_load_misses.walk_pending,dtlb_store_misses.walk_pending,ept.walk_pending,cycles}:W
   -> cpu/umask=0x10,(null)=0x186a3,event=0x85/
   -> cpu/umask=0x10,(null)=0x1e8483,event=0x8/
   -> cpu/umask=0x10,(null)=0x1e8483,event=0x49/
   -> cpu/umask=0x10,(null)=0x1e8483,event=0x4f/
  itlb_misses.walk_pending: 
8085772 16010162799 16010162799
  dtlb_load_misses.walk_pending: 
28134579 16010162799 16010162799
  dtlb_store_misses.walk_pending: 
7276535 16010162799 16010162799
  ept.walk_pending: 2 
16010162799 16010162799
  cycles: 
315140605 16010162799 16010162799
   Performance counter stats for 'system wide':
           8,085,772      itlb_misses.walk_pending  #      0.1 Page_Walks_Utilization
          28,134,579      dtlb_load_misses.walk_pending
           7,276,535      dtlb_store_misses.walk_pending
                   2      ept.walk_pending
         315,140,605      cycles
         2.
002333181 seconds time elapsed
  #
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/1582581564-184429-6-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>