Skip to content

[fix](kt-kernel): Drop Python-loaded weights after C++ weight loading in LlamafileMoEWrapper #1695

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
chenht2022 merged 1 commit into from
Dec 12, 2025
Merged

[fix](kt-kernel): Drop Python-loaded weights after C++ weight loading in LlamafileMoEWrapper #1695

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions kt-kernel/python/utils/llamafile.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -217,3 +217,6 @@ def load_weights(self, physical_to_logical_map_cpu: Optional[torch.Tensor] = Non
# Load weights
self.cpu_infer.submit(self.moe.load_weights_task(physical_to_logical_map_cpu.data_ptr()))
self.cpu_infer.sync()

# Drop original weights after loading
self.weights_to_keep = None
Comment on lines +221 to +222
Copy link
Contributor

@gemini-code-assist gemini-code-assist bot Dec 10, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

medium

While setting self.weights_to_keep = None correctly frees up the memory, a cleaner approach would be to remove the self.weights_to_keep member variable entirely.

The tensors (gate_data, up_data, down_data) are local to the load_weights method and will remain in scope until the method returns. Since self.cpu_infer.sync() blocks until the C++ copy is complete, the lifetime of these local variables is sufficient to ensure the memory is valid for the C++ backend.

This makes self.weights_to_keep redundant. You could consider a refactoring to simplify the code:

  1. Remove self.weights_to_keep = None from the __init__ method (line 135).
  2. Remove the assignment self.weights_to_keep = (gate_data, up_data, down_data) on line 182.
  3. Remove this newly added code block.

This would make the lifetime management implicit and rely on standard Python garbage collection, resulting in cleaner, more idiomatic code.