On Thu, Nov 30, 2023 at 12:30:27PM -0800, Shakeel Butt wrote: > 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? I can't think of any reason why we would want swappiness interpreted differently if it's provided at proactive reclaim time vs globally. Did you have something in mind here?
