On Thu 30-11-23 07:36:53, Dan Schatzberg wrote: [...] > In contrast, I argue in favor of a swappiness setting not as a way to implement > custom reclaim algorithms but rather to bias the balance of anon vs file due to > differences of proactive vs reactive reclaim. In this context, swappiness is the > existing interface for controlling this balance and this patch simply allows for > it to be configured differently for proactive vs reactive reclaim. I do agree that swappiness is a better interface than explicit anon/file but the problem with swappiness is that it is more of a hint for the reclaim rather than a real control. Just look at get_scan_count and its history. Not only its range has been extended also the extent when it is actually used has been changing all the time and I think it is not a stretch to assume that trend to continue. Now if we extend the user interface to trigger the reclaim do we expect that we always do SCAN_EQUAL if a user specifies swappiness or are we OK that the implementation is free to ignore that "hint"? -- Michal Hocko SUSE Labs