Kill slurmd remaining processes on upgrade

m/common/slurm.nix

@@ -1,6 +1,14 @@
-{ ... }:
+{ lib, ... }:
 
 {
+  systemd.services.slurmd.serviceConfig = {
+    # Kill all processes in the control group on stop/restart. This will kill
+    # all the jobs running, so ensure that we only upgrade when the nodes are
+    # not in use. See:
+    # https://github.com/NixOS/nixpkgs/commit/ae93ed0f0d4e7be0a286d1fca86446318c0c6ffb
+    # https://bugs.schedmd.com/show_bug.cgi?id=2095#c24
+    KillMode = lib.mkForce "control-group";
+  };
   services.slurm = {
     client.enable = true;
     controlMachine = "hut";