High CPU usage on Mongo server, but Mongo seems to be idle

with this version of mongostat, on linux, how can I show the “dirty %” field ?

mongostat --version
mongostat version: 100.5.0
git version: 460c7e26f65c4ce86a0b99c46a559dccaba3a07d
Go version: go1.16.3
os: linux
arch: amd64
compiler: gc

insert query update delete getmore command flushes mapped vsize res faults qrw arw net_in net_out conn time
*0 *0 1 1094 0 2|0 0 0B 1.54G 111M 0 0|0 0|0 2.55m 18.3k 16 Nov 2 19:05:57.139