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Anything that does >>>>> folio_rmap_remove_ptes can cause the folio to be deferred split if it gets partially >>>>> unmapped. >>>> >>>> Right, but it's easy to exclude zone-device folios here. So the real question is: do you want to deal with deferred splits or not? >>>> >>>> If not, then just disable it right from the start. >>>> >>> >>> I agree, I was trying to avoid special casing device private folios unless needed to the extent possible >> >> By introducing a completely separate split logic :P >> >> Jokes aside, we have plenty of zone_device special-casing already, no harm >> in adding one more folio_is_zone_device() there. >> >> Deferred splitting is all weird already that you can call yourself fortunate >> if you don't have to mess with that for zone-device folios. >> >> Again, unless there is a benefit in having it. > > +1 on no deferred split for device folios. > > I'll add it to v3 to check that we do not do deferred splits on zone device folios Balbir