perf vendor events intel: Add NO_NMI_WATCHDOG metric constraint ...
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>
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