Fixes #1: Tweak a few more parameters for cluster SSH usage.

README.md

@@ -80,5 +80,5 @@ Here are a few of the results I've acquired in my testing:
 |--- |--- |--- |--- |
 | Turing Pi 2 (4x CM4 @ 1.5 GHz) | 44.942 Gflops | 24.5W | 1.83 Gflops/W |
 | Turing Pi 2 (4x CM4 @ 2.0 GHz) | 51.327 Gflops | 33W | 1.54 Gflops/W |
-| DeskPi Super6c (6x CM4 @ 1.5 GHz) | TODO Gflops | TODOW | TODO Gflops/W |
+| DeskPi Super6c (6x CM4 @ 1.5 GHz) | 57.634 Gflops | 40W | 1.44 Gflops/W |
 | M2 MacBook Air (1x M2 @ 3.5 GHz, in Docker) | 104.68 Gflops | TODOW | TODO Gflops/W |

example.config.yml

@@ -6,12 +6,9 @@ hpl_root: /opt/top500
 ssh_user: pi
 ssh_user_home: /home/pi
 
-# Use this option if running on a single node.
+# Replace ansible_memtotal_mb with cluster memory total if running on cluster.
 ram_in_gb: "{{ ( ansible_memtotal_mb / 1024 * 0.75 ) | int | abs }}"
 
-# Use this option if running on multiple nodes in a cluster; calculate manually.
-# ram_in_gb: "44"
-
 # Count the nodes for accurate HPL.dat calculations.
 nodecount: "{{ ansible_play_hosts | length | int }}"
 
@@ -21,6 +18,8 @@ nodecount: "{{ ansible_play_hosts | length | int }}"
 hpl_dat_opts:
   # sqrt((Memory in GB * 1024 * 1024 * 1024 * Node count) / 8) * 0.9
   Ns: "{{ (((((ram_in_gb | int) * 1024 * 1024 * 1024 * (nodecount | int)) / 8) | root) * 0.90) | int }}"
-  NBs: 192
-  Ps: 2
-  Qs: 2
+  NBs: 256
+  # (P * Q) should be roughly equivalent to total core count, with Qs higher.
+  # If running on a single system, Ps should be 1 and Qs should be core count.
+  Ps: 1
+  Qs: 4

main.yml

@@ -178,6 +178,15 @@
         ssh {{ ssh_user }}@{{ item }} -o StrictHostKeyChecking=accept-new date
       loop: "{{ host_ips }}"
 
+    - name: Write chunk of hosts information to the hosts file.
+      ansible.builtin.blockinfile:
+        path: /etc/hosts
+        marker: "# {mark} Ansible MPI host {{ item }}"
+        block: |
+          {{ hostvars[item].ansible_default_ipv4.address }} {{ item }} {{ item | replace('.local', '') }}
+      loop: "{{ groups['cluster'] }}"
+      become: true
+
 - name: Run linpack benchmark.
   hosts: cluster
   become: false

templates/mpi-node-config.j2

@@ -1,3 +1,3 @@
 {% for host in groups['cluster'] %}
-{{ hostvars[host].ansible_default_ipv4.address }}:4
-{% endfor %}
+{{ hostvars[host].ansible_default_ipv4.address }}:{{ hostvars[host].ansible_processor_vcpus }}
+{% endfor %}