'tripleo_ovs_dpdk_lcore_list' should be optional

This parameter should be optional as only the first core in the mask
will be used to repin all ovs-vswitchd threads.
Leaving this parameter blank (and as a consequence, not setting
'dpdk-lcore-mask') allows all non-dpdk threads to float on the original
cpu set.

Change-Id: Ia9e001e2b1987f00a960cdf106eaa8e84dc4d71a
Signed-off-by: Christophe Fontaine <cfontain@redhat.com>

doc/source/roles/role-tripleo-ovs-dpdk.rst

@@ -22,14 +22,18 @@ Role Defaults
 - ``tripleo_ovs_dpdk_pmd_core_list``
 
   - **Description**: (*Mandatory*) List of PMD Cores for DPDK. Its a
-    comma-separated string of logical cores.
+    comma-separated string of logical cores. These core should be part
+    of ``isolcpus`` kernel parameter and be excluded from ``NovaComputeCpuDedicatedSet``
+    and from ``NovaComputeCpuSharedSet``
   - **Default**: ``''``
   - **Examples**: ``'1,13'``
 
 - ``tripleo_ovs_dpdk_lcore_list``
 
-  - **Description**: (*Mandatory*) List of lcores for DPDK. Its a
+  - **Description**: (*Optional*) List of lcores for DPDK. Its a
     comma-separated string of logical cores.
+    All ovs-vswitchd threads will be pinned to the first core declared
+    in the mask.
   - **Default**: ``''``
   - **Examples**: ``'0,12'``
 

tripleo_ansible/roles/tripleo_ovs_dpdk/molecule/default/converge.yml

@@ -27,8 +27,9 @@
         tripleo_ovs_dpdk_socket_memory: "1024,1024"
         tripleo_ovs_dpdk_emc_insertion_probablity: 10
 
-# By removing tripleo_ovs_dpdk_emc_insertion_probablity from the vars,
-# which was set by earlier play, should remove this key from the ovs db.
+# By removing tripleo_ovs_dpdk_emc_insertion_probablity and
+# tripleo_ovs_dpdk_lcore_list from the vars, which were set by earlier play,
+# should remove these keys from the ovs db.
 - name: Converge
   hosts: all
   tasks:
@@ -37,5 +38,4 @@
         tasks_from: "config.yml"
       vars:
         tripleo_ovs_dpdk_pmd_core_list: "1,13-15"
-        tripleo_ovs_dpdk_lcore_list: "0,12"
         tripleo_ovs_dpdk_socket_memory: "1024,1024"

tripleo_ansible/roles/tripleo_ovs_dpdk/molecule/default/tests/test_default.py

@@ -46,18 +46,17 @@ def test_positive_pmd(host):
     assert val == "e002"
 
 
-def test_positive_lcore(host):
-    other_config = get_config(host)
-    val = other_config['dpdk-lcore-mask'].replace('"', '')
-    assert val == "1001"
-
-
 def test_positive_socket_mem(host):
     other_config = get_config(host)
     val = other_config['dpdk-socket-mem'].replace('"', '')
     assert val == "1024,1024"
 
 
+def test_positive_lcore(host):
+    other_config = get_config(host)
+    assert 'dpdk-lcore-mask' not in other_config
+
+
 def test_positive_validator_threads(host):
     other_config = get_config(host)
     assert 'n-revalidator-threads' not in other_config

tripleo_ansible/roles/tripleo_ovs_dpdk/tasks/config.yml

@@ -19,11 +19,6 @@
     msg: "List of PMD cores cannot be empty - tripleo_ovs_dpdk_pmd_core_list"
   when: not tripleo_ovs_dpdk_pmd_core_list|string or tripleo_ovs_dpdk_pmd_core_list == 'null'
 
-- name: Check valid input for tripleo_ovs_dpdk_lcore_list
-  fail:
-    msg: "List of DPDK lcores cannot be empty - tripleo_ovs_dpdk_lcore_list"
-  when: not tripleo_ovs_dpdk_lcore_list|string or tripleo_ovs_dpdk_lcore_list == 'null'
-
 - name: Check valid input for tripleo_ovs_dpdk_socket_memory
   fail:
     msg: "Socket Memory cannot be empty - tripleo_ovs_dpdk_socket_memory"
@@ -38,7 +33,7 @@
     value: "{{ tripleo_ovs_dpdk_pmd_core_list | cpu_mask }}"
   when: tripleo_ovs_dpdk_pmd_core_list|string
 
-- name: Apply DPDK lcores config
+- name: Set DPDK lcores config
   openvswitch_db:
     table: open_vswitch
     record: .
@@ -47,6 +42,15 @@
     value: "{{ tripleo_ovs_dpdk_lcore_list | cpu_mask }}"
   when: tripleo_ovs_dpdk_lcore_list|string
 
+- name: Remove DPDK lcores config
+  openvswitch_db:
+    state: absent
+    table: open_vswitch
+    record: .
+    col: other_config
+    key: dpdk-lcore-mask
+  when: not tripleo_ovs_dpdk_lcore_list|string or tripleo_ovs_dpdk_lcore_list == 'null'
+
 - name: Add memory channels to dpdk extra
   set_fact:
     tripleo_ovs_dpdk_extra_internal: "{{ tripleo_ovs_dpdk_extra }} -n {{ tripleo_ovs_dpdk_memory_channels }}"