wjddn279 commented on code in PR #58365: URL: https://github.com/apache/airflow/pull/58365#discussion_r2538886572
########## airflow-core/src/airflow/utils/gc_utils.py: ########## @@ -0,0 +1,44 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +from __future__ import annotations + +import gc +from functools import wraps + + +def with_gc_freeze(func): + """ + Freeze the GC before executing the function and unfreeze it after execution. + + This is done to prevent memory increase due to COW (Copy-on-Write) by moving all + existing objects to the permanent generation before forking the process. After the + function executes, unfreeze is called to ensure there is no impact on gc operations + in the original running process. Review Comment: > Does this mean that everything that exists before gc.freeze will never be released? No. All objects that were marked as belonging to the permanent generation due to `freeze` are unmarked again with `unfreeze` after the worker processes are spawned. Therefore, they participate in normal GC behavior, and this does not affect the scheduler’s operation. > how come the scheduler is such a high pid? <img width="1098" height="27" alt="image" src="https://github.com/user-attachments/assets/25ea4c0e-a7f7-4093-8a49-b054bbee1bc7"; /> In the result shown, the scheduler process has PID 7, which becomes even clearer if you check with `ps -ef`. The high PID you mentioned corresponds to a short-lived subprocess. It is a subprocess created by the worker, and because it is created for each task and then terminates, the PID keeps increasing. The screenshot of the benchmark results is from the `smem` command, so the process information may appear distorted. <img width="972" height="22" alt="image" src="https://github.com/user-attachments/assets/2144bdc6-b4da-4a41-b2b4-26a586b7f8c0"; /> -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
