On Thu 30-11-23 11:56:42, Johannes Weiner wrote: [...] > So I wouldn't say it's merely a reclaim hint. It controls a very > concrete and influential factor in VM decision making. And since the > global swappiness is long-established ABI, I don't expect its meaning > to change significantly any time soon. As I've said I am more worried about potential future changes which would modify existing, reduce or add more corner cases which would be seen as a change of behavior from the user space POV. That means that we would have to be really explicit about the fact that the reclaim is free to override the swappiness provided by user. So essentially a best effort interface without any actual guarantees. That surely makes it harder to use. Is it still useable? Btw. IIRC these concerns were part of the reason why memcg v2 doesn't have swappiness interface. If we decide to export swappiness via memory.reclaim interface does it mean we will do so on per-memcg level as well? -- Michal Hocko SUSE Labs
