On Mon, Jul 04, 2022 at 02:31:17PM +0200, Vlastimil Babka wrote: > On 6/24/22 14:54, Mel Gorman wrote: > > Currently the PCP lists are protected by using local_lock_irqsave to > > prevent migration and IRQ reentrancy but this is inconvenient. Remote > > draining of the lists is impossible and a workqueue is required and every > > task allocation/free must disable then enable interrupts which is > > expensive. > > > > As preparation for dealing with both of those problems, protect the lists > > with a spinlock. The IRQ-unsafe version of the lock is used because IRQs > > are already disabled by local_lock_irqsave. spin_trylock is used in > > preparation for a time when local_lock could be used instead of > > lock_lock_irqsave. > > ^ local_lock_irqsave? > More appropriate given how the series evolved would be; spin_trylock is used in combination with local_lock_irqsave() but later will be replaced with a spin_trylock_irqsave when the local_lock is removed. -- Mel Gorman SUSE Labs
