---
- name: Configure kernel memory overcommit
  ansible.posix.sysctl:
    name: vm.overcommit_memory
    value: "1"
    state: present
    sysctl_set: true
    reload: true

- name: Check if transparent_hugepage is set in GRUB
  ansible.builtin.shell: grep -E '^GRUB_CMDLINE_LINUX_DEFAULT=.*transparent_hugepage=' /etc/default/grub
  register: thp_check
  changed_when: false
  failed_when: false

- name: Add transparent_hugepage if not present
  ansible.builtin.lineinfile:
    path: /etc/default/grub
    regexp: '^(GRUB_CMDLINE_LINUX_DEFAULT="[^"]*)"$'
    line: '\1 transparent_hugepage=madvise"'
    backrefs: true
  when: thp_check.rc != 0
  notify: Update GRUB
  register: grub_updated

- name: Check current THP runtime setting
  ansible.builtin.shell: cat /sys/kernel/mm/transparent_hugepage/enabled
  register: current_thp
  changed_when: false

- name: Disable THP at runtime (if not already set to madvise)
  ansible.builtin.shell: |
    echo madvise > /sys/kernel/mm/transparent_hugepage/enabled
    echo madvise > /sys/kernel/mm/transparent_hugepage/defrag
  when: "'[madvise]' not in current_thp.stdout"

- name: Warn user about reboot requirement
  ansible.builtin.debug:
    msg: |
      WARNING: GRUB configuration has been updated with transparent_hugepage=madvise
      A REBOOT IS REQUIRED for this change to take effect permanently.
      The setting has been applied at runtime temporarily.
  when: grub_updated is changed