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>> + >> + folio_split_unref(folio); >> pgmap->ops->folio_free(folio); >> percpu_ref_put_many(&folio->pgmap->ref, nr); >> break; > > This breaks folio_free implementations like nouveau_dmem_folio_free > which checks the folio order and act upon that. > Maybe add an order parameter to folio_free or let the driver handle the split? Passing an order parameter might be better to avoid exposing core MM internals by asking drivers to undo compound pages. Best Regards, Yan, Zi