On 05/10/2023 09:15, David Hildenbrand wrote: > On 05.10.23 09:37, Ryan Roberts wrote: >> On 02/10/2023 13:58, David Hildenbrand wrote: >>>> [...] >>>> >>>> My concern is that the "fresh start" is not as simple as it appears. I've come >>>> to the conclusion that if we have a new interface, then it should really be a >>>> strict superset of THP to make it extensible in future. But that opens >>>> questions >>> >>> ^ +1 >>> >>>> about how you configure PMD-sized allocations when both interfaces disagree. >>>> For >>>> "enabled" its fairly straightforward; you can do a logical OR. But its less >>>> clear how to handle disagreement over defrag. And then you have huge_zero_page >>>> and khugepaged etc, which might just stay with THP. But eventually we will >>> >>> Probably we want everything that THP had (khugepaged, zeropage, ...) also on >>> some (selected?) smaller orders. >>> >>>> probably want to do async collapse for smaller order folios too, and at that >>>> point you have to duplicate all those controls... So I concluded that actually >>>> it is cleaner to just bolt on a small-order extension to THP. I've updated all >>>> the docs, and that was pretty simple to do, which usually suggests that the >>>> extension is purely additive and shouldn't be confusing. >>> >>> Fine with me. I don't quite like bitmaps exposed to user space, though. Just >>> having a user-readable list or a "directory" with various options as files might >>> be cleaner ... >>> >>>> >>>> Take a look at the patches, then make a judgement ;-) >>>> >>> >>> ... but we'll discuss it there :) >>> >> >> David, FYI, the patches are posted at [1] (you're cc'ed) and have been in >> mm-unstable for nearly a week - so I guess they will go to mm-stable soon by >> default. So if you want to object to any of it, now's the time ;-). > > I just did :P > > Note that I'm distracted by a tiny human being. I should be back at work tomorrow. Ahh - congratulations! > > Hopefully other people that participated in the discussions can review and ack > in the meantime. That would certainly be nice (hint to everyone else on the thread ;-) > > IMHO there really is no need to rush at this point. I have a couple of selfish reasons; I was hoping to get it into v6.7 since I was thinking that would be the next LTS, but I've just done the maths again, and it looks like it will be v6.6, so I guess I've missed it anyway. The other is that I would like to move focus to other changes that build on this, and that's difficult while this is still not merged. >
