main.yml

---

#
# installs Linux perf @ /usr/local/bin/perf
#

- stat:
    path: /usr/local/bin/perf
  register: linux_perf
  tags: linux_perf

- name: install perf on linux
  tags: linux_perf
  when: not (linux_perf.stat.exists | bool)
  block:
    - name: Clean path
      file:
        state: absent
        path: "{{ tmp_folder }}"

    - name: Get current kernel version
      ansible.builtin.shell: uname -r | awk -F. '{print $1"."$2}'
      register: kernel_version
      changed_when: false

    - name: Download Linux source code
      git:
        repo: https://github.com/torvalds/linux.git
        version: "v{{ kernel_version.stdout }}"
        depth: 1
        dest: "{{ tmp_folder }}/linux"

    - name: Install packages
      package:
        name: "{{ package }}"
        state: present
      loop_control:
        loop_var: package
      with_items: "{{ packages }}"

    - name: build Linux perf
      shell: make -j{{ ansible_processor_cores | default(1) }}
      args:
        chdir: "{{ tmp_folder }}/linux/tools/perf"

    - name: install Linux perf
      shell: "cp {{ tmp_folder }}/linux/tools/perf/perf /usr/local/bin/perf"

    - name: Clean path
      file:
        state: absent
        path: "{{ tmp_folder }}"

- name: Allow monitoring
  ansible.builtin.lineinfile:
    create: yes
    dest: "/etc/sysctl.d/20-perf.conf"
    line: "{{ item.line }}"
    regexp: "{{ item.regexp }}"
  notify: update sysctl settings
  with_items:
  - { regexp: "kernel.perf_event_paranoid", line: "kernel.perf_event_paranoid = 2" }
  tags: linux_perf