On Thu, Nov 30, 2023 at 11:47 AM Dan Schatzberg <schatzberg.dan@xxxxxxxxx> wrote: > > On Thu, Nov 30, 2023 at 11:56:42AM -0500, 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. > > I want to add to this last point. While swappiness does not have > terribly well-defined semantics - it is the (only?) existing mechanism > to control balance between anon and file reclaim. I'm merely > advocating for the ability to adjust swappiness during proactive > reclaim separately from reactive reclaim. To what degree the behavior > and semantics of swappiness change is a bit orthogonal here. Let me ask my question in this chain as it might have been missed: Whatever the semantics of swappiness are (including the edge cases like no swap, file_is_tiny, trim cache), should the reclaim code treat the global swappiness and user-provided swappiness differently?