levelzero/xelink: accumulate subdevice link bandwidths in parents

Fix f207b0f moved root BWs
to subdevices, which means there's nothing in root anymore
whenever there are subdevices.
Accumulate in parents so that parent BWs are identical to what
they were before the fix.

Signed-off-by: Brice Goglin <[email protected]>

Author: bgoglin

doc/hwloc.doxy

@@ -2452,6 +2452,9 @@ or between two subdevices of the same parent.
 
 The matrix interconnects all LevelZero devices and subdevices (if any),
 even if some of them may have no link at all.
+
+The bandwidths of links between subdevices are accumulated in the
+bandwidth between their parents.
 </dd>
 <dt>NVLinkBandwidth (NVML)</dt>
 <dd>This is the matrix of unidirectional NVLink bandwidths between

hwloc/topology-levelzero.c

@@ -382,6 +382,7 @@ struct hwloc_levelzero_ports {
   unsigned nr;
   struct hwloc_levelzero_port {
     hwloc_obj_t osdev;
+    hwloc_obj_t parent_osdev;
     zes_fabric_port_properties_t props;
     zes_fabric_port_state_t state;
   } *ports;
@@ -443,12 +444,14 @@ hwloc__levelzero_ports_get(zes_device_handle_t dvh,
                   i, hports->ports[id].props.subdeviceId);
       if (hports->ports[id].props.subdeviceId < nr_sub_osdevs) {
         hports->ports[id].osdev = sub_osdevs[hports->ports[id].props.subdeviceId];
+        hports->ports[id].parent_osdev = root_osdev;
       } else {
         hwloc_debug("    no such subdevice exists, ignoring\n");
         continue;
       }
     } else {
       hports->ports[id].osdev = root_osdev;
+      hports->ports[id].parent_osdev = NULL;
     }
 
     res = zesFabricPortGetState(ports[i], &hports->ports[id].state);
@@ -549,7 +552,14 @@ hwloc__levelzero_ports_connect(struct hwloc_topology *topology,
           if (iindex<0 || jindex<0)
             continue;
           bws[iindex*oarray->nr+jindex] += hports->ports[i].state.rxSpeed.bitRate >> 20; /* MB/s */
-          /* TODO: way to accumulate subdevs bw into rootdevs? tranformation? different matrix? */
+          if (hports->ports[i].parent_osdev && hports->ports[j].parent_osdev) {
+            /* also accumulate in root devices */
+            iindex = hwloc__levelzero_osdev_array_find(oarray, hports->ports[i].parent_osdev);
+            jindex = hwloc__levelzero_osdev_array_find(oarray, hports->ports[j].parent_osdev);
+            if (iindex<0 || jindex<0)
+              continue;
+            bws[iindex*oarray->nr+jindex] += hports->ports[i].state.rxSpeed.bitRate >> 20; /* MB/s */
+          }
           gotbw++;
         }
       }