Merge pull request sap-linuxlab#886 from berndfinger/issue-885-thp-fl…

…exibility

sap_hana_preconfigure: Allow setting THP to any possible value

roles/sap_hana_preconfigure/README.md

@@ -416,6 +416,12 @@ Set this parameter to `true` to modify the Grub boot command line.<br>
 By default, the role will run `grub2-mkconfig` to update the Grub configuration if necessary.<br>
 Set this parameter to `false` if this is not desired.<br>
 
+### sap_hana_preconfigure_thp
+- _Type:_ `str`
+- _Default:_ ``
+
+Override the default setting for THP, which is determined automatically by the role, depending on the RHEL version.
+
 ### sap_hana_preconfigure_db_group_name
 - _Type:_ `str`
 
@@ -449,4 +455,4 @@ Available values: `HANA`, `NETWEAVER+HANA`, `S4HANA-APP+DB`, `S4HANA-DBSERVER`
 (SUSE specific) On Azure, TCP timestamps, reuse and recycle should be disabled.<br>
 If the variable is set, an override file for saptune will be created (/etc/saptune/override/2382421) to set net.ipv4.tcp_timestamps and net.ipv4.tcp_tw_reuse to 0.<br>
 Set this parameter to `true` on Azure.<br>
-<!-- END Role Variables -->
+<!-- END Role Variables -->

roles/sap_hana_preconfigure/defaults/main.yml

@@ -166,6 +166,10 @@ sap_hana_preconfigure_run_grub2_mkconfig: true
 # It will be used to configure process limits as per step "Configuring Process Resource Limits" of SAP note 2772999.
 # Example: See README.md
 
+# sap_hana_preconfigure_thp: (not defined by default)
+# Override the default setting for THP, which is determined automatically by the role, depending on the RHEL version.
+# Can be one of 'always', 'madvise', or 'never'.
+
 # (SUSE specific) Version of saptune to install.
 # It is recommended to install latest version by keeping this variable empty.
 # This will replace the current installed version if present, even downgrade if necessary.

roles/sap_hana_preconfigure/handlers/main.yml

@@ -75,16 +75,10 @@
   listen: __sap_hana_preconfigure_grubby_update_handler
   notify: __sap_hana_preconfigure_reboot_handler
 
-- name: "Run grubby for disabling THP"
-  ansible.builtin.command: grubby --args="transparent_hugepage=never" --update-kernel=ALL
+- name: "Run grubby for setting THP to '{{ __sap_hana_preconfigure_fact_thp }}'"
+  ansible.builtin.command: grubby --args="transparent_hugepage={{ __sap_hana_preconfigure_fact_thp }}" --update-kernel=ALL
   changed_when: true
-  listen: __sap_hana_preconfigure_grubby_thp_never_handler
-  notify: __sap_hana_preconfigure_reboot_handler
-
-- name: "Run grubby for setting THP to madvise"
-  ansible.builtin.command: grubby --args="transparent_hugepage=madvise" --update-kernel=ALL
-  changed_when: true
-  listen: __sap_hana_preconfigure_grubby_thp_madvise_handler
+  listen: __sap_hana_preconfigure_grubby_thp_handler
   notify: __sap_hana_preconfigure_reboot_handler
 
 - name: Reboot the managed node

roles/sap_hana_preconfigure/meta/argument_specs.yml

@@ -341,6 +341,18 @@ argument_specs:
         required: false
         type: bool
 
+      sap_hana_preconfigure_thp:
+        default: ''
+        description:
+          - Override the default setting for THP, which is determined automatically by the role, depending on the RHEL version.
+        choices:
+          - ''
+          - 'always'
+          - 'madvise'
+          - 'never'
+        required: false
+        type: str
+
       sap_hana_preconfigure_db_group_name:
         description:
           - Use this parameter to specify the name of the RHEL group which is used for the database processes.

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

@@ -27,6 +27,7 @@
       ansible.builtin.set_fact:
         __sap_hana_preconfigure_fact_thp: 'never'
       when:
+        - sap_hana_preconfigure_thp is undefined or sap_hana_preconfigure_thp | length == 0
         - ansible_distribution == 'RedHat'
         - ansible_distribution_major_version == '7' or
           ansible_distribution_major_version == '8' or
@@ -37,10 +38,17 @@
       ansible.builtin.set_fact:
         __sap_hana_preconfigure_fact_thp: 'madvise'
       when:
+        - sap_hana_preconfigure_thp is undefined or sap_hana_preconfigure_thp | length == 0
         - ansible_distribution == 'RedHat'
         - ansible_distribution_major_version == '9' and
             __sap_hana_preconfigure_fact_ansible_distribution_minor_version | int >= 2
 
+    - name: Set fact for THP if 'sap_hana_preconfigure_thp' is defined
+      ansible.builtin.set_fact:
+        __sap_hana_preconfigure_fact_thp: "{{ sap_hana_preconfigure_thp }}"
+      when:
+        - sap_hana_preconfigure_thp is defined and sap_hana_preconfigure_thp
+
     - name: Assert that 'transparent_hugepage={{ __sap_hana_preconfigure_fact_thp }}' is in GRUB_CMDLINE_LINUX in /etc/default/grub
       ansible.builtin.assert:
         that: "'transparent_hugepage={{ __sap_hana_preconfigure_fact_thp }}' in __sap_hana_preconfigure_register_default_grub_cmdline_thp_assert.stdout"

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

@@ -6,52 +6,48 @@
     src: /proc/cmdline
   register: __sap_hana_preconfigure_register_proc_cmdline_thp
 
-- name: Set THP to 'never' at boot time
-  ansible.builtin.command: /bin/true
-  notify: __sap_hana_preconfigure_grubby_thp_never_handler
-  changed_when: true
+- name: Set fact for THP, RHEL up to RHEL 9.1
+  ansible.builtin.set_fact:
+    __sap_hana_preconfigure_fact_thp: 'never'
   when:
+    - sap_hana_preconfigure_thp is undefined or sap_hana_preconfigure_thp | length == 0
     - ansible_distribution == 'RedHat'
-    - ansible_distribution_major_version == '8' or
+    - ansible_distribution_major_version == '7' or
+      ansible_distribution_major_version == '8' or
       ansible_distribution_version == '9.0' or
       ansible_distribution_version == '9.1'
-    - not ( __sap_hana_preconfigure_register_proc_cmdline_thp['content'] | b64decode | regex_findall('transparent_hugepage=never') )
-  tags: grubconfig
 
-- name: Set THP to 'madvise' at boot time
-  ansible.builtin.command: /bin/true
-  notify: __sap_hana_preconfigure_grubby_thp_madvise_handler
-  changed_when: true
+- name: Set fact for THP, RHEL 9.2 and later
+  ansible.builtin.set_fact:
+    __sap_hana_preconfigure_fact_thp: 'madvise'
   when:
+    - sap_hana_preconfigure_thp is undefined or sap_hana_preconfigure_thp | length == 0
     - ansible_distribution == 'RedHat'
     - ansible_distribution_major_version == '9' and
         __sap_hana_preconfigure_fact_ansible_distribution_minor_version | int >= 2
-    - not ( __sap_hana_preconfigure_register_proc_cmdline_thp['content'] | b64decode | regex_findall('transparent_hugepage=madvise') )
+
+- name: Set fact for THP if 'sap_hana_preconfigure_thp' is defined
+  ansible.builtin.set_fact:
+    __sap_hana_preconfigure_fact_thp: "{{ sap_hana_preconfigure_thp }}"
+  when:
+    - sap_hana_preconfigure_thp is defined and sap_hana_preconfigure_thp
+
+- name: Set THP to '{{ __sap_hana_preconfigure_fact_thp }}' at boot time
+  ansible.builtin.command: /bin/true
+  notify: __sap_hana_preconfigure_grubby_thp_handler
+  changed_when: true
+  when: not ( __sap_hana_preconfigure_register_proc_cmdline_thp['content'] | b64decode | regex_findall('transparent_hugepage=' + __sap_hana_preconfigure_fact_thp) )
   tags: grubconfig
 
 - 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 'never' on the running system
-  ansible.builtin.shell: echo 'never' > /sys/kernel/mm/transparent_hugepage/enabled
+- 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:
-    - ansible_distribution == 'RedHat'
-    - ansible_distribution_major_version == '8' or
-      ansible_distribution_version == '9.0' or
-      ansible_distribution_version == '9.1'
-    - __sap_hana_preconfigure_register_thp_status_before.stdout.split('[')[1].split(']')[0] != 'never'
-
-- name: Set THP to 'madvise' on the running system
-  ansible.builtin.shell: echo 'madvise' > /sys/kernel/mm/transparent_hugepage/enabled
-  changed_when: true
-  when:
-    - ansible_distribution == 'RedHat'
-    - ansible_distribution_major_version == '9' and
-        __sap_hana_preconfigure_fact_ansible_distribution_minor_version | int >= 2
-    - __sap_hana_preconfigure_register_thp_status_before.stdout.split('[')[1].split(']')[0] != 'madvise'
+  when: __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