Move ModelConfig from config/__init__.py to config/model.py

[lengrongfu]

Purpose

Part of #18953

Test Plan

Test Result

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[hmellor]

If you are going to be moving PoolerConfig, can you please convert it's fields into InitVars as I did for MultiModalConfig (you can use this as reference)

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @lengrongfu.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[lengrongfu]

If you are going to be moving PoolerConfig, can you please convert it's fields into InitVars as I did for MultiModalConfig (you can use this as reference)

Look this pr #24659 after, i know how to convert PoolerConfig fields into InitVar.

I’d like to ask for your advice: what are the benefits of using the InitVar type instead? Currently, using object references between structures is a common practice. Could you explain this to me?

I know that InitVar is only used during initialization, but the parameter pooler_config: Optional["PoolerConfig"] = field(init=False) will still be used after initialization.

I’d really appreciate your input.

[hmellor]

what are the benefits of using the InitVar type instead?

My comment was perhaps more relevant for multimodal as the individual multimodal fields were duplicated. The duplication means that you could read the same field from 2 places, i.e. model_config.mm_processor_cache_gb and model_config.multimodal_config.mm_processor_cache_gb. Changing one does not necessarily change the other, which can be risky at runtime. InitVar means you can still pass mm_processor_cache_gb to ModelConfig(...), but the value is only stored in MultiModalConfig.

In this case we just have pooler_config_override.

I don't like pooler_config_override actually, it would be much better to just pass the pooler config instead. Perhaps this is something for a follow up PR.

[hmellor]

Forget using InitVar for now, but could you please move the PoolerConfig to pooler.py?

[hmellor]

Since I have moved PoolerConfig separately and have an open PR which also moves ModelConfig (while making some QoL improvements), I'm going to close this as superseded by #25252

Thank you for the PR though!