redis: variable to disable transparent hugepage (default: do nothing)

CHANGELOG.md

@@ -25,6 +25,7 @@ The **patch** part changes is incremented if multiple releases happen the same m
 * lxc-solr: set homedir and port at install
 * minifirewall: whitelist deb.freexian.com
 * redis: some values should be quoted
+* redis: variable to disable transparent hugepage (default: do nothing)
 * squid: whitelist deb.freexian.com
 
 ### Fixed

redis/defaults/main.yml

@@ -61,5 +61,9 @@ redis_sentinel_install: False
 
 redis_default_server_disabled: False
 
+# Set to Null to leave as is
+# Set to "always", "madvise" or "never" for custom value
+redis_sysctl_transparent_hugepage_enabled: Null
+
 general_alert_email: "root@localhost"
 log2mail_alert_email: Null

redis/handlers/main.yml

@@ -23,3 +23,8 @@
   service:
     name: log2mail
     state: restarted
+
+- name: restart sysfsutils
+  service:
+    name: sysfsutils
+    state: restarted

redis/tasks/main.yml

@@ -3,7 +3,19 @@
 - set_fact:
     redis_restart_handler_name: "{{ redis_restart_if_needed | bool | ternary('restart redis', 'restart redis (noop)') }}"
 
-- name: Redis is installed.
+- name: Linux kernel overcommit memory setting is enabled
+  sysctl:
+    name: "vm.overcommit_memory"
+    value: "1"
+    sysctl_file: "/etc/sysctl.d/evolinux-redis.conf"
+    state: present
+    reload: yes
+
+- name: Customize Kernel Transparent Huge Page
+  include: thp.yml
+  when: redis_sysctl_transparent_hugepage_enabled is not none
+
+- name: Redis is installed
   apt:
     name:
       - redis-server
@@ -13,7 +25,7 @@
     - redis
     - packages
 
-- name: Redis Sentinel is installed.
+- name: Redis Sentinel is installed
   apt:
     name: "redis-sentinel"
     state: present
@@ -22,14 +34,6 @@
     - packages
   when: redis_sentinel_install | bool
 
-- name: Linux kernel overcommit memory setting is enabled
-  sysctl:
-    name: "vm.overcommit_memory"
-    value: "1"
-    sysctl_file: "/etc/sysctl.d/evolinux-redis.conf"
-    state: present
-    reload: yes
-
 - name: Get Redis version
   shell: "redis-server -v | grep -Eo '(v=\\S+)' | cut -d'=' -f 2 | grep -E '^([0-9]|\\.)+$'"
   changed_when: false

redis/tasks/thp.yml

@@ -0,0 +1,34 @@
+---
+
+- name: sysfsutils is installed
+  apt:
+    name:
+      - sysfsutils
+    state: present
+  tags:
+    - redis
+    - packages
+    - kernel
+
+- name: Check possible values for THP
+  assert:
+    that: redis_sysctl_transparent_hugepage_enabled is in ['always', 'madvise', 'never']
+    msg: "redis_sysctl_transparent_hugepage_enabled has incorrect value : '{{ redis_sysctl_transparent_hugepage_enabled }}' not in ['always', 'madvise', 'never']"
+  tags:
+    - redis
+    - kernel
+
+- name: "Set THP to {{ redis_sysctl_transparent_hugepage_enabled }} at boot"
+  lineinfile:
+    path: /etc/sysfs.conf
+    line: kernel/mm/transparent_hugepage/enabled = {{ redis_sysctl_transparent_hugepage_enabled }}
+    regexp: "kernel/mm/transparent_hugepage/enabled"
+  tags:
+    - redis
+    - kernel
+
+- name: "Set THP to {{ redis_sysctl_transparent_hugepage_enabled }} for this boot"
+  shell: "echo '{{ redis_sysctl_transparent_hugepage_enabled }}' >> /sys/kernel/mm/transparent_hugepage/enabled"
+  tags:
+    - redis
+    - kernel