[profiler] record nccl version in distributed info (#121044)

Summary: Add a field of NCCL version in distributed info if backend is NCCL

Differential Revision: D54432888

Pull Request resolved: https://github.com/pytorch/pytorch/pull/121044
Approved by: https://github.com/aaronenyeshi

torch/profiler/profiler.py

@@ -268,13 +268,18 @@ class _KinetoProfile:
         if not dist.is_available() or not dist.is_initialized():
             return None
 
-        return {
-            "backend": dist.get_backend(),
+        backend = dist.get_backend()
+        dist_info = {
+            "backend": backend,
             "rank": dist.get_rank(),
             "world_size": dist.get_world_size(),
             "pg_count": dist.get_pg_count(),
             "pg_config": dist.distributed_c10d._get_all_pg_configs(),
         }
+        if backend == "nccl":
+            nccl_version = torch.cuda.nccl.version()
+            dist_info["nccl_version"] = ".".join(str(v) for v in nccl_version)
+        return dist_info
 
     def _memory_profile(self) -> MemoryProfile:
         required = ("record_shapes", "profile_memory", "with_stack")