On Wed, Apr 07, 2021 at 09:24:12PM +0100, Mel Gorman wrote: > Why local_lock? PREEMPT_RT considers the following sequence to be unsafe > as documented in Documentation/locking/locktypes.rst > > local_irq_disable(); > raw_spin_lock(&lock); Almost, the above is actually OK on RT. The problematic one is: local_irq_disable(); spin_lock(&lock); That doesn't work on RT since spin_lock() turns into a PI-mutex which then obviously explodes if it tries to block with IRQs disabled. And it so happens, that's exactly the one at hand.
