Possible dual license for rbtree ?

From: Daniel Diaz
Date: Mon Apr 03 2023 - 05:22:19 EST


Dear Linux maintainers,

This is a question about a possible dual license for the rbtree implementation (lib/rbtree.c).
Please apologize if it is not the right place to ask.
Thank you for personally CC me in the answers/comments posted to the list in response to this post.

Looking for an efficient red-black tree implementation in C, I discovered the wonderful rbtree utility. I really appreciate the clever approach of this « invasive » implementation on the top of which one can build his specific maps. I saw this rbtree implementation is famous and widely mentioned but its usage is limited by its GPL license.

Could you consider extending this license by a dual license as allowed by docs.kernel.org/process/license-rules.html which states the some individual files can be provided under a dual license including MIT, BSD, etc.

Would then it be possible to release rbtree under a dual license more permissive, e.g. MIT ?
Be sure this would be very appreciated by a lot of C programmers !

This comes down to modyfy the SPDX descriptions of lib/rbtree.c and include/rbtree.h, include/rbtree_augmented.h, include/rbtree_types.h as follows:

    SPDX-License-Identifier: GPL-2.0-or-later OR MIT

Thank you for your attention.

Daniel