The term "pull request" comes from "git request-pull" which is the tool used by kernel subsystem maintainers to send emails to Linus to request he git pull from their branches (and merge them). This usage long predates the somewhat unrelated "pull request" feature of source forges (like GitHub) and is not confusing to kernel developers (the target audience of Linus's email).

The analogy to GitHub-like "pull requests" in the kernel workflow is "git send-email" (or "b4 send" nowadays) which sends patch series as individual emails that can be reviewed inline as a plain-text email and are applied onto maintainers' trees (usually with something akin to "git cherry-pick"). I still find this system to be a superior method to GitHub's "pull requests" (you can send review comments to commit descriptions -- which I believe Gerrit supports, but GitHub definitely doesn't -- and everything is sanely threaded since it's all email).

Here's an example pull request email from the start of the week[1], containing some VFS changes to be included in 6.17-rc1.

[1]: https://lore.kernel.org/all/20250725-vfs-misc-599b4aef8eaa@b...