Input lag during high disk usage

What version of Codex is running?

codex-cli 0.79.0

What subscription do you have?

Pro

Which model were you using?

gpt-5.2-codex xhigh

What platform is your computer?

Darwin 25.1.0 arm64 arm

What issue are you seeing?

Any time I ran pnpm install, or git clone -q; whenever there was high disk usage, I would see considerable input lag. I've reproduced this over a few multiplexers tmux, zellij, and openmux. I've also tested it on just regular Ghostty.

What steps can reproduce the bug?

1. Open ghostty or a similar terminal and split a pane/window.
2. Run codex in one pane
3. Run git clone -q https://github.com/zellij-org/zellij in another
4. Try to spam or type in the codex pane and see the input lag (sometimes ranging between 1-2 seconds before the key renders to the chat input box).

What is the expected behavior?

There should be no lag. Spamming an empty terminal with a pane that is cloning zellij does not incur the same keyboard input lag.

Additional information

_No response_