On Wed, May 03, 2023 at 04:25:30PM -1000, Tejun Heo wrote: > I see. I'm a bit skeptical about the performance angle given that the hot > path can be probably made really cheap even with lookups. In most cases, > it's just gonna be an extra pointer deref and a few more arithmetics. That > can show up in microbenchmarks but it's not gonna be much. The benefit of > going that route would be the tracking thing being mostly self contained. The only way to do it with a single additional pointer deref would be with a completely statically sized hash table without chaining - it'd have to be open addressing. More realistically you're looking at ~3 dependent loads.