sap_hana_preconfigure: Further improvements for setting kernel args

- Only use dict contents for determining kernel command line
  dependencies for RHEL releases
- Set and display the grubby command line before calling the handler

Signed-off-by: Bernd Finger <bfinger@redhat.com>

Author: berndfinger

roles/sap_hana_preconfigure/handlers/main.yml

@@ -74,7 +74,7 @@
 
 - name: "Run grubby for configuring kernel command line entries for SAP"
   ansible.builtin.command:
-    cmd: grubby --args="{{ __sap_hana_preconfigure_boot_command_line_args_final | trim }}" --update-kernel=ALL
+    cmd: "{{ __sap_hana_preconfigure_fact_grubby_command }}"
   changed_when: true
   listen: __sap_hana_preconfigure_grubby_update_handler
   notify: __sap_hana_preconfigure_reboot_handler

roles/sap_hana_preconfigure/tasks/RedHat/generic/configure-c-states-for-lower-latency.yml

@@ -10,4 +10,5 @@
   loop_control:
     loop_var: __sap_hana_preconfigure_kernel_arg_line_item
   when:
+    - __sap_hana_preconfigure_boot_command_line_args['c-states']['arch'] is defined
     - ansible_architecture in __sap_hana_preconfigure_boot_command_line_args['c-states']['arch']

roles/sap_hana_preconfigure/tasks/RedHat/generic/configure-thp.yml

@@ -12,31 +12,39 @@
   ansible.builtin.set_fact:
     __sap_hana_preconfigure_fact_thp: "{{ __sap_hana_preconfigure_boot_command_line_args['thp']['args'][0].split('=')[1] }}"
   when:
+    - __sap_hana_preconfigure_boot_command_line_args['thp']['arch'] is defined
     - sap_hana_preconfigure_thp is undefined or sap_hana_preconfigure_thp | length == 0
 
-- name: Add boot command line args for configuring THP
-  ansible.builtin.set_fact:
-    __sap_hana_preconfigure_boot_command_line_args_final: >-
-      {{ __sap_hana_preconfigure_boot_command_line_args_final + ['transparent_hugepage=' + __sap_hana_preconfigure_fact_thp] }}
+- name: Add boot command line args for configuring THP if applicable
+  when:
+    - (sap_hana_preconfigure_thp is defined and sap_hana_preconfigure_thp | length > 0)
+      or __sap_hana_preconfigure_boot_command_line_args['thp']['arch'] is defined
+  block:
 
-- name: Configure - Get initial status of THP
-  ansible.builtin.command: cat /sys/kernel/mm/transparent_hugepage/enabled
-  register: __sap_hana_preconfigure_register_thp_status_before
-  changed_when: false
+    - name: Add boot command line args for configuring THP
+      ansible.builtin.set_fact:
+        __sap_hana_preconfigure_boot_command_line_args_final: >-
+          {{ __sap_hana_preconfigure_boot_command_line_args_final
+          + ['transparent_hugepage=' + __sap_hana_preconfigure_fact_thp] }}
 
-- name: Set THP to '{{ __sap_hana_preconfigure_fact_thp }}' on the running system
-  ansible.builtin.shell: echo '{{ __sap_hana_preconfigure_fact_thp }}' > /sys/kernel/mm/transparent_hugepage/enabled
-  changed_when: true
-  when:
-    - not ansible_check_mode
-    - __sap_hana_preconfigure_register_thp_status_before.stdout.split('[')[1].split(']')[0] != __sap_hana_preconfigure_fact_thp
-
-- name: Configure - Get the status of THP
-  ansible.builtin.command: cat /sys/kernel/mm/transparent_hugepage/enabled
-  register: __sap_hana_preconfigure_register_thp_status
-  ignore_errors: true
-  changed_when: false
-
-- name: Display the status of THP
-  ansible.builtin.debug:
-    var: __sap_hana_preconfigure_register_thp_status.stdout_lines, __sap_hana_preconfigure_register_thp_status.stderr_lines
+    - name: Configure - Get initial status of THP
+      ansible.builtin.command: cat /sys/kernel/mm/transparent_hugepage/enabled
+      register: __sap_hana_preconfigure_register_thp_status_before
+      changed_when: false
+
+    - name: Set THP to '{{ __sap_hana_preconfigure_fact_thp }}' on the running system
+      ansible.builtin.shell: echo '{{ __sap_hana_preconfigure_fact_thp }}' > /sys/kernel/mm/transparent_hugepage/enabled
+      changed_when: true
+      when:
+        - not ansible_check_mode
+        - __sap_hana_preconfigure_register_thp_status_before.stdout.split('[')[1].split(']')[0] != __sap_hana_preconfigure_fact_thp
+
+    - name: Configure - Get the status of THP
+      ansible.builtin.command: cat /sys/kernel/mm/transparent_hugepage/enabled
+      register: __sap_hana_preconfigure_register_thp_status
+      ignore_errors: true
+      changed_when: false
+
+    - name: Display the status of THP
+      ansible.builtin.debug:
+        var: __sap_hana_preconfigure_register_thp_status.stdout_lines, __sap_hana_preconfigure_register_thp_status.stderr_lines

roles/sap_hana_preconfigure/tasks/RedHat/generic/enable-tsx.yml

@@ -9,7 +9,5 @@
   loop_control:
     loop_var: __sap_hana_preconfigure_kernel_arg_line_item
   when:
+    - __sap_hana_preconfigure_boot_command_line_args['tsx']['arch'] is defined
     - ansible_architecture in __sap_hana_preconfigure_boot_command_line_args['tsx']['arch']
-    - ansible_distribution_major_version | int >= 9 or
-      (ansible_distribution_major_version == '8' and
-       __sap_hana_preconfigure_fact_ansible_distribution_minor_version | int >= 3)

roles/sap_hana_preconfigure/tasks/RedHat/generic/set-boot-kernel-args.yml

@@ -77,7 +77,20 @@
 
 - name: Display kernel args to be set
   ansible.builtin.debug:
-    msg: "Kernel args to be set: {{ __sap_hana_preconfigure_fact_kernel_args_to_be_set }}"
+    msg: "Kernel args to be set: '{{ __sap_hana_preconfigure_fact_kernel_args_to_be_set }}'"
+
+- name: Construct the grubby command for configuring the kernel command line entries
+  ansible.builtin.set_fact:
+    __sap_hana_preconfigure_fact_grubby_command: >-
+      grubby --args="{{ __sap_hana_preconfigure_fact_kernel_args_to_be_set | join(' ') | trim }}" --update-kernel=ALL
+  when:
+    - __sap_hana_preconfigure_fact_kernel_args_to_be_set | length > 0
+
+- name: Display the grubby command to be run
+  ansible.builtin.debug:
+    msg: "Grubby command: '{{ __sap_hana_preconfigure_fact_grubby_command }}'"
+  when:
+    - __sap_hana_preconfigure_fact_kernel_args_to_be_set | length > 0
 
 # Reason for noqa: The command does not change anything but if we set 'changed_when: true',
 # the handler will not be notified.