feat(pgsql): param node_hugepage_count accepts value -1 to set hugepage automatically (only PG 15+)

nr_hugepages calculated by `shared_memory_size_in_huge_pages`

if `node_hugepage_count` or `node_hugepage_ratio` changed, it will full backup the pg_cls and restart it gracefully

support usage:
  - `pig install`
  - `bin/pgsql-add <pg_cls>`
  -  `bin/pgsql-add <pg_cls> <ip>`
     only new nodes changed and restarted
  - `pgsql.yml -l <pg_cls> -t pg_hugepage`

calculation rules:
  1. `shared_memory_size_in_huge_pages` (from PG15+): if `node_hugepage_count` is -1 and huge_pages (from PG) != off
  2. if `node_hugepage_count` > 0
     - `shared_memory_size_in_huge_pages`: if `shared_memory_size_in_huge_pages` > `node_hugepage_count`
     - `node_hugepage_count`
  3. disable hugepage if `node_hugepage_count` is 0
  4. if `node_hugepage_ratio` > 0
    - `shared_memory_size_in_huge_pages`: if `shared_memory_size_in_huge_pages` > pages calculated from `node_hugepage_ratio`
    - page value calculated from `node_hugepage_ratio`

All above rules and usages are tested successfully on Rocky Linux 9

Author: waitingsong

roles/node/defaults/main.yml

@@ -38,7 +38,8 @@ node_disable_swap: false          # disable node swap, use with caution
 node_static_network: true         # preserve dns resolver settings after reboot
 node_disk_prefetch: false         # setup disk prefetch on HDD to increase performance
 node_kernel_modules: [ softdog, br_netfilter, ip_vs, ip_vs_rr, ip_vs_wrr, ip_vs_sh ]
-node_hugepage_count: 0            # number of 2MB hugepage, take precedence over ratio
+node_hugepage_count: 0            # number of 2MB hugepage, take precedence over ratio,
+                                  # -1: use shared_memory_size_in_huge_pages calculated by pg (PG 15+ available)
 node_hugepage_ratio: 0            # node mem hugepage ratio, 0 disable it by default
 node_overcommit_ratio: 0          # node mem overcommit ratio, 0 disable it by default
 node_tune: oltp                   # node tuned profile: none,oltp,olap,crit,tiny

roles/pgsql/tasks/main.yml

@@ -55,6 +55,21 @@
   tags: [ patroni, pg_launch ]
   when: patroni_enabled|bool
 
+#--------------------------------------------------------------#
+# pg hugepages                                     [pg_hugepage]
+#--------------------------------------------------------------#
+- import_tasks: pg_hugepage.yml
+  when: patroni_enabled|bool
+  tags: [ patroni, pg_launch, pg_hugepage ]
+
+#--------------------------------------------------------------#
+# patroni restart pg_cls gracefully                 [pt_restart]
+#--------------------------------------------------------------#
+- name: patroni restart pg_cls gracefully
+  include_tasks: grace_patroni_restart.yml
+  when: patroni_enabled|bool and (pt_restart is defined and pt_restart|bool)
+  tags: [ patroni, pg_launch, pt_restart, pg_hugepage ]
+
 #--------------------------------------------------------------#
 # Users                                                [pg_user]
 #--------------------------------------------------------------#

roles/pgsql/tasks/pg_hugepage.yml

@@ -0,0 +1,62 @@
+---
+#--------------------------------------------------------------#
+# Enable hugepage for pg and restart pg cluster    [pg_hugepage]
+# if `node_hugepage_count` or `node_hugepage_ratio` changed, it will full backup the pg_cls and restart it gracefully
+# support usage:
+#   - `pig install`
+#   - `bin/pgsql-add <pg_cls>`
+#   - `pgsql.yml -l <pg_cls> -t pg_hugepage`
+#--------------------------------------------------------------#
+# calculation rules:
+#   1. `shared_memory_size_in_huge_pages` (from PG15+): if `node_hugepage_count` is -1 and huge_pages (from PG) != off
+#   2. if `node_hugepage_count` > 0
+#      - `shared_memory_size_in_huge_pages`: if `shared_memory_size_in_huge_pages` > `node_hugepage_count`
+#      - `node_hugepage_count`
+#   3. disable hugepage if `node_hugepage_count` is 0
+#   4. if `node_hugepage_ratio` > 0
+#      - `shared_memory_size_in_huge_pages`: if `shared_memory_size_in_huge_pages` > pages calculated from `node_hugepage_ratio`
+#      - page value calculated from `node_hugepage_ratio`
+# All above rules and usages are tested successfully on Rocky Linux 9
+#--------------------------------------------------------------#
+
+- name: Set default value
+  set_fact:
+    curr_nr_hugepages: 0
+    new_nr_hugepages: 0
+  changed_when: false
+
+
+- name: enable hugepage for pg
+  tags: pg_hugepage
+  vars:
+  block:
+    - import_tasks: util/pg_read_hugepage.yml
+
+    - name: calculate hugepage need update
+      set_fact:
+        hugepages_need_update: "{{ new_nr_hugepages|int != curr_nr_hugepages|int }}"
+      changed_when: false
+
+    - name: set pt_restart according to hugepages_need_update
+      set_fact:
+        pt_restart: "{{ hugepages_need_update|bool }}"
+      changed_when: false
+
+    - name: print nr_hugepages values
+      when: new_nr_hugepages is defined and curr_nr_hugepages is defined
+      debug:
+        msg: |
+          curr_nr_hugepages: {{ curr_nr_hugepages|trim }}, new_nr_hugepages: {{ new_nr_hugepages|trim }},
+           hugepages_need_update: {{ hugepages_need_update|bool }},
+           pt_restart: {{ pt_restart|bool }}
+      changed_when: false
+
+    - name: full backup pg before hugepage update if has primary
+      include_tasks: util/pg_backup.yml
+      when: hugepages_need_update|bool and pg_role == 'primary'
+
+    - name: update hugepage
+      include_tasks: util/pg_write_hugepage.yml
+      when: hugepages_need_update|bool
+
+...