On Mon, Apr 18, 2022 at 12:43:43PM -0700, Linus Torvalds wrote: > Similarly, tsk_is_pi_blocked() will disable the plug flush. Bah, I'm forever confused by that clause... I did ask for a comment at some point but that never seems to have happened. https://lore.kernel.org/all/20190816160626.12742-1-bigeasy@xxxxxxxxxxxxx/T/#md983b64256814c046cec9ec875f4a975029b0daa Seems to indicate it is about scheduling while holding a lock and the unplug then leading to a deadlock.
