[Log] Reduce duplicate log

[yewentao256]

Purpose

For example

INFO 03-17 15:12:19 [dp_utils.py:30] Using CPU all reduce to synchronize DP padding between ranks.
INFO 03-17 15:12:19 [dp_utils.py:30] Using CPU all reduce to synchronize DP padding between ranks.
INFO 03-17 15:12:19 [dp_utils.py:30] Using CPU all reduce to synchronize DP padding between ranks.
INFO 03-17 15:12:19 [dp_utils.py:30] Using CPU all reduce to synchronize DP padding between ranks.

->

INFO 03-17 15:12:19 [dp_utils.py:30] Using CPU all reduce to synchronize DP padding between ranks.

[gemini-code-assist]

Code Review

This pull request addresses an issue of duplicate log messages, particularly in distributed setups. The changes systematically replace standard logging calls (logger.info, logger.debug, logger.warning) with their *_once counterparts and add the scope="local" parameter to existing *_once calls. This ensures that log messages intended to be displayed only once per worker do not get duplicated across multiple workers or ranks, significantly improving log clarity. The modifications are applied consistently across various components of the vLLM codebase, including compilation, scheduling, and model execution layers. The implementation is correct and effectively resolves the described problem.

[MatthewBonanni]

LGTM