SetDev for nccl

paddle/fluid/framework/parallel_executor.cc

@@ -358,7 +358,7 @@ struct NCCLAllReduceOpHandle : public OpHandle {
         }
 
         auto &nccl_ctx = member_->communication_streams_.at(dev_id);
-
+        cudaSetDevice(dev_id);
         platform::dynload::ncclAllReduce(
             buffer, buffer, numel, static_cast<ncclDataType_t>(dtype), ncclSum,
             nccl_ctx.comm, nccl_ctx.stream());
@@ -519,7 +519,6 @@ void ParallelExecutor::ConstructDependencyGraph(
             var.name_ = og;
             var.version_ = vars.size() - 1;
             op_handle->outputs_.emplace_back(&var);
-
             op_handle->dev_ctx_[p] = member_->CommunicationDevCtx(p);
           }
         }