On Mon, Jun 08, 2026 at 01:13:42PM +0200, Vlastimil Babka (SUSE) wrote: > On 6/8/26 13:02, Vlastimil Babka (SUSE) wrote: > > On 6/8/26 10:33, Michael S. Tsirkin wrote: > >> Further, on architectures with aliasing caches, upstream with init_on_alloc > > > > It seems those are niche architectures so we can ignore that part for perf > > purposes; the other reason why user_alloc_needs_zeroing() would be true is > > booting with init_on_alloc. > > OK I misread how user_alloc_needs_zeroing() works wrt init_on_alloc, as it's > negated. But you're changing that anyway to skip that user zeroing, right? > > " > This series eliminates that double-zeroing by moving the zeroing > into the post_alloc_hook + propagating the "host > already zeroed this page" information through the buddy allocator. > " > > So relying on "everything in buddy is zeroed" would still work I'd think. >
This regresses for anything that previously didn't zero on free or alloc, which is most kernel allocations. I think the scope of this set has increased too much based on early feedback to fix the userland-initiated allocations piece along with the balloon/reporting/double-zero piece. That's making all of this difficult to continue following. ~Gregory
