On Wed, 28 Jun 2023, Gerald Schaefer wrote: > > As discussed in the other thread, we would rather go with less complexity, > possibly switching to an approach w/o the list and fragment re-use in the > future. For now, as a first step in that direction, we can try with not > adding fragments back only for pte_free_defer(). Here is an adjusted > version of your patch, copying most of your pte_free_defer() logic and > also description, tested with LTP and all three of your patch series applied: Thanks, Gerald: I don't mind abandoning my 13/12 SLAB_TYPESAFE_BY_RCU patch (posted with fewer Cc's to the s390 list last week), and switching to your simpler who-cares-if-we-sometimes-don't-make-maximal-use-of-page patch. But I didn't get deep enough into it today to confirm it - and disappointed that you've found it necessary to play with pt_frag_refcount in addition to _refcount and HH bits. No real problem with that, but my instinct says it should be simpler. Tomorrow... Hugh