On 12/13/22 16:45, Nico Pache wrote: > Since commit 1378a5ee451a ("mm: store compound_nr as well as > compound_order") the page[1].compound_nr must be explicitly set to 0 if > calling set_compound_order(page, 0). > > This can lead to bugs if the caller of set_compound_order(page, 0) forgets > to explicitly set compound_nr=0. An example of this is commit ba9c1201beaa > ("mm/hugetlb: clear compound_nr before freeing gigantic pages") There has been some recent work in this area. The latest patch being, https://lore.kernel.org/linux-mm/20221213212053.106058-1-sidhartha.kumar@xxxxxxxxxx/ -- Mike Kravetz