The failing hugetlb vmsplice() COW tests keep confusing people, and having tests that have been failing for years and likely will keep failing for years to come because nobody cares enough is rather suboptimal. Let's mark them as XFAIL and document why fixing them is not that easy as it would appear at first sight. More details can be found in [1], especially around how hugetlb pages cannot really be overcommitted, and why we don't particularly care about these vmsplice() leaks for hugetlb -- in contrast to ordinary memory. [1] https://lore.kernel.org/all/8b42a24d-caf0-46ef-9e15-0f88d47d2f21@xxxxxxxxxx/ Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Muchun Song <muchun.song@xxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> David Hildenbrand (2): selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL mm/hugetlb: document why hugetlb uses folio_mapcount() for COW reuse decisions mm/hugetlb.c | 7 ++ tools/testing/selftests/mm/cow.c | 106 +++++++++++++++++++++---------- 2 files changed, 78 insertions(+), 35 deletions(-) -- 2.44.0
