Adjust documentation and behaviour of cpuset

1. Detail the caveats and specific situations and ref the documentation
which will provide more details.

2. Always install the configs, but use /etc/default/ceph-osd-cpuset to
control if the script does anything or not (so, the "osd" cset set is
always active just not set in a special way.

roles/pvc/tasks/ceph/main.yml

@@ -117,14 +117,6 @@
     - ceph-mon@{{ ansible_hostname }}
     - ceph-mgr@{{ ansible_hostname }}
 
-# This is separate from the block to allow *disabling* of the config without removing it
-- name: install ceph-osd-cpuset controller config
-  template:
-    src: ceph/ceph-osd-cpuset-enable.j2
-    dest: /etc/default/ceph-osd-cpuset
-  when:
-    - pvc_shield_osds_enable is defined
-
 # System OSD CPU shielding activation
 - block:
     - name: install packages
@@ -134,6 +126,11 @@
           - numactl
         state: latest
 
+    - name: install ceph-osd-cpuset controller config
+      template:
+        src: ceph/ceph-osd-cpuset-enable.j2
+        dest: /etc/default/ceph-osd-cpuset
+
     - name: install ceph-osd-cpuset script
       template:
         src: ceph/ceph-osd-cpuset.j2
@@ -167,12 +164,9 @@
         enabled: yes
 
     - debug:
-        msg: "NOTICE: cpuset configs have NOT been applied to the running system. This node must be rebooted to apply these changes."
-      when: systemd_file_cpuset.changed or systemd_file_osd.changed
+        msg: "NOTICE: Any cpuset configs have NOT been applied to the running system. This node must be rebooted to apply these changes."
   tags: pvc-ceph-cpuset
   when:
     - pvc_shield_osds_enable is defined
-    - pvc_shield_osds_cset is defined
-    - pvc_shield_osds_cset | selectattr('hostname', 'equalto', inventory_hostname) | list | count > 0
 
 - meta: flush_handlers

roles/pvc/templates/ceph/ceph-osd-cpuset.j2

@@ -4,10 +4,16 @@
 
 # This script is designed to prepare the cpusets for use by Ceph OSDs, VMs, and other system resources.
 # Libvirt does not make this easy with any way to globally set its CPUs, so we must do this trickery.
+{% if pvc_shield_osds_cset is defined %}
 {% set cset_host = pvc_shield_osds_cset | selectattr('hostname', 'equalto', inventory_hostname) %}
 
 A_OSD_CPUS=( {{ cset_host[0]['osd_cset'] | join(' ') }} )
 A_SYS_CPUS=()
+{% else %}
+
+A_OSD_CPUS=()
+A_SYS_CPUS=()
+{% endif %}
 
 CPU_INFO="$( lscpu )"
 
@@ -41,7 +47,9 @@ for i in $( seq 0 $(( ${CPU_COUNT} - 1 )) ); do
     fi
 done
 
-if [[ $( cat /etc/default/ceph-osd-cpuset ) == "True" ]]; then
+{% raw %}
+if [[ $( cat /etc/default/ceph-osd-cpuset ) == "True" && ${#A_OSD_CPUS[@]} -gt 0 ]]; then
+{% endraw %}
     # Convert arrays into CSV
     OSD_MEMS="$( IFS=, ; echo "${A_OSD_MEMS[*]}" )"
     OSD_CPUS="$( IFS=, ; echo "${A_OSD_CPUS[*]}" )"

roles/pvc/templates/ceph/ceph-osd-cpuset.service.j2

@@ -1,6 +1,5 @@
 # PVC Ceph OSD cpuset service unit
 # {{ ansible_managed }}
-{% set cset_host = pvc_shield_osds_cset | selectattr('hostname', 'equalto', inventory_hostname) %}
 [Unit]
 Description = Ceph OSD cpuset shield creation
 Before = ceph-osd@.service libvirtd.service