On 19 Mar 2026, at 12:06, Chunyu Hu wrote: > When thp is not available, just skip the collape tests to avoid the false > negative. > > Without the change, run with a thp disabled kernel: > ./run_vmtests.sh -t madv_guard -n 1 > <snip/> > # RUN guard_regions.anon.collapse ... > # guard-regions.c:2217:collapse:Expected madvise(ptr, size, > MADV_NOHUGEPAGE) (-1) == 0 (0) > # collapse: Test terminated by assertion > # FAIL guard_regions.anon.collapse > not ok 2 guard_regions.anon.collapse > <snip/> > # RUN guard_regions.shmem.collapse ... > # guard-regions.c:2217:collapse:Expected madvise(ptr, size, > MADV_NOHUGEPAGE) (-1) == 0 (0) > # collapse: Test terminated by assertion > # FAIL guard_regions.shmem.collapse > not ok 32 guard_regions.shmem.collapse > <snip/> > # RUN guard_regions.file.collapse ... > # guard-regions.c:2217:collapse:Expected madvise(ptr, size, > MADV_NOHUGEPAGE) (-1) == 0 (0) > # collapse: Test terminated by assertion > # FAIL guard_regions.file.collapse > not ok 62 guard_regions.file.collapse > <snip/> > # FAILED: 87 / 90 tests passed. > # 17 skipped test(s) detected. Consider enabling relevant config options to > improve coverage. > # Totals: pass:70 fail:3 xfail:0 xpass:0 skip:17 error:0 > > With this change, run with thp disabled kernel: > ./run_vmtests.sh -t madv_guard -n 1 > <snip/> > # RUN guard_regions.anon.collapse ... > # SKIP Transparent Hugepages not available > # OK guard_regions.anon.collapse > ok 2 guard_regions.anon.collapse # SKIP Transparent Hugepages not available > <snip/> > # RUN guard_regions.file.collapse ... > # SKIP Transparent Hugepages not available > # OK guard_regions.file.collapse > ok 62 guard_regions.file.collapse # SKIP Transparent Hugepages not available > <snip/> > # RUN guard_regions.shmem.collapse ... > # SKIP Transparent Hugepages not available > # OK guard_regions.shmem.collapse > ok 32 guard_regions.shmem.collapse # SKIP Transparent Hugepages not > available > <snip/> > # PASSED: 90 / 90 tests passed. > # 20 skipped test(s) detected. Consider enabling relevant config options to > improve coverage. > # Totals: pass:70 fail:0 xfail:0 xpass:0 skip:20 error:0 > > CC: Li Wang <[email protected]> > Signed-off-by: Chunyu Hu <[email protected]> > --- > Changes in v4: > - use thp_available instead of thp_is_enabled() as when thp is set to > never, madvise(MADV_COLLAPSE) will still succeed by design. So a > failure in madvise(MADV_COLLAPSE) on guard region will verify guard > region denies it. This is suggested from AI. > - removed the 'Reviewed-by' and 'Acked-by' as the code changes. Sorry for > that but it seems the changes is a little huge? (1 out of 2 lines).. > Changes in v3: > - commit message: update the log snippet with where the fail happens and > add the '-n1' to the command. > - fix the 'false positive' to 'false negative' > - add reviwed by from Mike > Changes in v2: > - add reviewed by from Zi and Lorenzo > - add acked-by from David > --- > tools/testing/selftests/mm/guard-regions.c | 4 ++++ > 1 file changed, 4 insertions(+) >
Reviewed-by: Zi Yan <[email protected]> Best Regards, Yan, Zi

