[fleet_executor] Dist model bug fixer (#39207)

Author: FeixLiu

paddle/fluid/distributed/fleet_executor/dist_model.cc

@@ -487,21 +487,25 @@ bool DistModel::PrepareFeedAndFetch() {
  if (feeds_.size() == 0) {
  LOG(ERROR) << "Feed ops are needed for the first pp stage.";
  return false;
+ }
+ } else {
+ if (feeds_.size() > 0) {
+ LOG(WARNING) << "Feed op is found in the non-first stage of pp.";
  } else {
- LOG(WARNING) << "No feed ops in non-first pp stage.";
+ LOG(INFO) << "No feed ops in non-first pp stage.";
  }
- } else if (feeds_.size() > 0) {
- LOG(WARNING) << "Feed op is found in the non-first stage of pp.";
  }
  if (IsPPLastStage(config_)) {
  if (fetches_.size() == 0) {
- LOG(ERROR) << "Fetch op is needed for the last pp stage.";
- return false;
+ LOG(WARNING) << "No fetch op was found in the last pp stage. Make sure "
+ "the result has been sent to frist pp stage.";
+ }
+ } else {
+ if (fetches_.size() > 0) {
+ LOG(WARNING) << "Fetch op is found in the non-last stage of pp.";
  } else {
- LOG(WARNING) << "No fetch op in non-last pp stage.";
+ LOG(INFO) << "No fetch op in non-last pp stage.";
  }
- } else if (fetches_.size() > 0) {
- LOG(WARNING) << "Fetch op is found in the non-last stage of pp.";
  }
  }
  return true;