On Tue, Jul 23, 2019 at 02:03:21PM +0100, Mel Gorman wrote: > On Tue, Jul 23, 2019 at 02:00:30PM +0200, Peter Zijlstra wrote: > > On Tue, Jul 23, 2019 at 12:42:48PM +0100, Mel Gorman wrote: > > > On Tue, Jul 23, 2019 at 11:48:30AM +0100, Matt Fleming wrote: > > > > Signed-off-by: Matt Fleming <[email protected]> > > > > Cc: "Suthikulpanit, Suravee" <[email protected]> > > > > Cc: Mel Gorman <[email protected]> > > > > Cc: "Lendacky, Thomas" <[email protected]> > > > > Cc: Borislav Petkov <[email protected]> > > > > > > Acked-by: Mel Gorman <[email protected]> > > > > > > The only caveat I can think of is that a future generation of Zen might > > > take a different magic number than 32 as their remote distance. If or > > > when this happens, it'll need additional smarts but lacking a crystal > > > ball, we can cross that bridge when we come to it. > > > > I just suggested to Matt on IRC we could do something along these lines, > > but we can do that later. > > > > That would seem fair but I do think it's something that could be done > later (maybe 1 release away?) to avoid a false bisection to this patch by > accident.
Quite agreed; changing reclaim_distance like that will affect a lot of hardware, while the current patch limits the impact to just AMD-Zen based bits. > I don't *think* there are any machines out there with a 1-hop > distance of 14 but if there is, your patch would make a difference to > MM behaviour. In the same context, it might make sense to rename the > value to somewhat reflective of the fact that "reclaim distance" affects > scheduler placement. No good name springs to mind at the moment. Yeah, naming sucks. Let us pain this bicycle shed blue!
