I never had much luck running mm selftests so I spent a couple of hours digging into why.
Looks like most of the reason is missing SKIP checks, so this series is just adding a bunch of those that I found. I did not do anything like all of them, just the ones I spotted in gup_longterm, gup_test, mmap, userfaultfd and memfd_secret.
It's a bit unfortunate to have to skip those tests when ftruncate() fails, but I don't have time to dig deep enough into it to actually make them pass - I observed these issues on both 9p and virtiofs. Probably it requires digging into the filesystem implementation
(An alternative might just be to mount a tmpfs in the test script).
I am also seeing some failures to allocate hugetlb pages in uffd-mp-mremap that I have not had time to fully understand, you can see those here:
https://gist.github.com/bjackman/af74c3a6e60975e6ff0d760cba1e05d2#file-userf...
Signed-off-by: Brendan Jackman jackmanb@google.com --- Changes in v2 (Thanks to Dev for the reviews): - Improve and cleanup some error messages - Add some extra SKIPs - Fix misnaming of nr_cpus variable in uffd tests - Link to v1: https://lore.kernel.org/r/20250220-mm-selftests-v1-0-9bbf57d64463@google.com
--- Brendan Jackman (9): selftests/mm: Report errno when things fail in gup_longterm selftests/mm: Fix assumption that sudo is present selftests/mm: Skip uffd-stress if userfaultfd not available selftests/mm: Skip uffd-wp-mremap if userfaultfd not available selftests/mm/uffd: Rename nr_cpus -> nr_threads selftests/mm: Print some details when uffd-stress gets bad params selftests/mm: Don't fail uffd-stress if too many CPUs selftests/mm: Skip map_populate on weird filesystems selftests/mm: Skip gup_longerm tests on weird filesystems
tools/testing/selftests/mm/gup_longterm.c | 45 ++++++++++++++++++---------- tools/testing/selftests/mm/map_populate.c | 7 +++++ tools/testing/selftests/mm/run_vmtests.sh | 22 +++++++++++--- tools/testing/selftests/mm/uffd-common.c | 8 ++--- tools/testing/selftests/mm/uffd-common.h | 2 +- tools/testing/selftests/mm/uffd-stress.c | 42 ++++++++++++++++---------- tools/testing/selftests/mm/uffd-unit-tests.c | 2 +- tools/testing/selftests/mm/uffd-wp-mremap.c | 5 +++- 8 files changed, 90 insertions(+), 43 deletions(-) --- base-commit: a3daad8215143340c0870c5489e599fd059037e9 change-id: 20250220-mm-selftests-2d7d0542face
Best regards,