On Mon 06-12-21 14:47:13, David Hildenbrand wrote: > On 06.12.21 14:06, Michal Hocko wrote: [...] > > This is certainly possible. But it a) adds a branch to the hotpath and > > b) it doesn't solve any other potential dereference of garbage node. > > I don't think a) is a problem but it's easy to measure. Let me just clarify on this one. This single particular branch will be indeed hard to match to any performance changes. On a single call of the allocator it is nothing. But it is a condition that will be executed by each caller while it won't ever trigger in most systems and workloads. In other words it will cause a lot of wasted cpu cycles long term. A more expensive one time initialization is worth in order to have allocator fast path lighter IMHO. -- Michal Hocko SUSE Labs
