Facebook/Meta Tackling Transparent Page Placement For Tiered-Memory Linux Systems

Back during the Linux 5.15 cycle Intel contributed an improvement for tiered memory systems where less used memory pages could be demoted to slower tiers of memory storage. But once demoted that kernel infrastructure didn't have a means of promoting those demoted pages back to the faster memory tiers should they become hot again, though now Facebook/Meta engineers have been working on such functionality...