Without NHC_CHECK_ALL=1, check_cpufreq_is_reasonable returns 1 and the node is marked offline as expected.

[root@fc99 ~]# nhc -v
Node Health Check starting.
Running check:  "check_fs_mount_rw -t "tmpfs" -s "tmpfs"                    -f "/dev/shm""
Running check:  "check_fs_mount_rw -t "tmpfs" -s "tmpfs"                    -f "/""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcHome"        -f "/home""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcScratch"     -f "/scratch""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcWork"        -f "/work""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcSoftware"    -f "/global/software""
Running check:  "check_fs_mount_rw -t "nfs"   -s "bulknetapp?:/Bulk"       -f "/bulk""
Running check:  "check_fs_used /scratch 95%"
Running check:  "check_fs_used /home    95%"
Running check:  "check_fs_used /work    95%"
Running check:  "check_fs_used /tmp     95%"
Running check:  "check_fs_used /bulk    95%"
Running check:  "check_file_test -r -w -x -d -k /tmp"
Running check:  "check_hw_swap_free 1048576"
Running check:  "check_file_contents /etc/rocky-release 'Rocky Linux release 8.4 (Green Obsidian)'"
Running check:  "check_file_contents /proc/version 'Linux version 4.18.0-348.23.1.el8_5.x86_64 (mockbuild@dal1-prod-builder001.bld.equ.rockylinux.org) (gcc version 8.5.0 20210514 (Red Hat 8.5.0-4) (GCC)) #1 SMP Wed Apr 27 15:32:52 UTC 2022'"
Running check:  "check_cmd_output -t 10 -e 'id slurm' -m 'uid=987(slurm) gid=983(slurm) groups=983(slurm)'"
Running check:  "check_cmd_output -t 10 -e 'id munge' -m 'uid=989(munge) gid=984(munge) groups=984(munge)'"
Running check:  "check_cpufreq_is_reasonable"
Node Health Check failed.  Check check_cpufreq_is_reasonable returned 1
ERROR:  nhc:  Health check failed:  Check check_cpufreq_is_reasonable returned 1
20221129 13:35:13 /usr/libexec/nhc/node-mark-offline fc99 Check check_cpufreq_is_reasonable returned 1
/usr/libexec/nhc/node-mark-offline:  Marking idle fc99 offline:  NHC: Check check_cpufreq_is_reasonable returned 1
ERROR:  nhc:  Health check failed:  Check check_cpufreq_is_reasonable returned 1


with NHC_CHECK_ALL=1, check_cpufreq_is_reasonable returns 1, but nhc brings the node back online

[root@fc99 ~]# nhc -v
Node Health Check starting.
Running check:  "export MARK_OFFLINE=1 NHC_CHECK_ALL=1"
Running check:  "check_fs_mount_rw -t "tmpfs" -s "tmpfs"                    -f "/dev/shm""
Running check:  "check_fs_mount_rw -t "tmpfs" -s "tmpfs"                    -f "/""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcHome"        -f "/home""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcScratch"     -f "/scratch""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcWork"        -f "/work""
Running check:  "check_fs_mount_rw -t "nfs"   -s "netapp?:/ArcSoftware"    -f "/global/software""
Running check:  "check_fs_mount_rw -t "nfs"   -s "bulknetapp?:/Bulk"       -f "/bulk""
Running check:  "check_fs_used /scratch 95%"
Running check:  "check_fs_used /home    95%"
Running check:  "check_fs_used /work    95%"
Running check:  "check_fs_used /tmp     95%"
Running check:  "check_fs_used /bulk    95%"
Running check:  "check_file_test -r -w -x -d -k /tmp"
Running check:  "check_hw_swap_free 1048576"
Running check:  "check_file_contents /etc/rocky-release 'Rocky Linux release 8.4 (Green Obsidian)'"
Running check:  "check_file_contents /proc/version 'Linux version 4.18.0-348.23.1.el8_5.x86_64 (mockbuild@dal1-prod-builder001.bld.equ.rockylinux.org) (gcc version 8.5.0 20210514 (Red Hat 8.5.0-4) (GCC)) #1 SMP Wed Apr 27 15:32:52 UTC 2022'"
Running check:  "check_cmd_output -t 10 -e 'id slurm' -m 'uid=987(slurm) gid=983(slurm) groups=983(slurm)'"
Running check:  "check_cmd_output -t 10 -e 'id munge' -m 'uid=989(munge) gid=984(munge) groups=984(munge)'"
Running check:  "check_cpufreq_is_reasonable"
20221129 13:35:24 [slurm] /usr/libexec/nhc/node-mark-online fc99
/usr/libexec/nhc/node-mark-online:  Marking fc99 online and clearing note (NHC: Check check_cpufreq_is_reasonable returned 1)
Node Health Check completed successfully (2s).