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Description of problem:
mem.vmstat.drop_pagecache & mem.vmstat.drop_slab metric values are always zero though the /proc/vmstat reflects them properly.
Version-Release number of selected component (if applicable):
pcp-5.0.2-5.el8.x86_64
How reproducible:
Steps to Reproduce:
1. drop the cache couple of times
$echo 3 > /proc/sys/vm/drop_caches
$ echo 3 > /proc/sys/vm/drop_caches
$ echo 2 > /proc/sys/vm/drop_caches
$ echo 2 > /proc/sys/vm/drop_caches
$ echo 1 > /proc/sys/vm/drop_caches
2. The /proc/vmstat has refelected the values:
$ cat /proc/vmstat | grep -i drop
drop_pagecache 2
drop_slab 2
3. but PCP is not able to read it properly. Its always zero:
$ pmrep mem.vmstat.drop_pagecache
m.v.drop_pagecache
count/s
N/A
0.000
0.000
0.000
0.000
0.000
$ pmrep mem.vmstat.drop_slab
m.v.drop_slab
count/s
N/A
0.000
0.000
^C
Actual results:
mem.vmstat.drop_pagecache & mem.vmstat.drop_pagecache metric values are always zero
Expected results:
They should reflect the real time values.
Additional info: