On 5/18/22 12:09, Johannes Weiner wrote: > However, with NUMA balancing now doing tier promotions, demotion is > part of the page aging process. Global reclaim demotes the coldest > toptier pages to secondary memory, where their life continues and from > which they have a chance to get promoted back. Essentially, tiered > memory systems have an LRU order that spans multiple nodes. Thanks for the detailed explanation. Ultimately, this was just intended as an optimization to make cgroup reclaim more efficient. But, I agree that ordering correctness should trump efficiency. Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
