The test requires at least 2 * (bytes/page_size) hugetlb memory, since we require identical number of hugepages for src and dst location. Fix this.
Along with the above, as explained in patch "selftests/mm/uffd-stress: Make test operate on less hugetlb memory", the racy nature of the test requires that we have some extra number of hugepages left beyond what is required. Therefore, stricten this constraint.
Fixes: 5a6aa60d1823 ("selftests/mm: skip uffd hugetlb tests with insufficient hugepages") Signed-off-by: Dev Jain dev.jain@arm.com --- tools/testing/selftests/mm/uffd-stress.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c index 40af7f67c407..3f6213ae0dd5 100644 --- a/tools/testing/selftests/mm/uffd-stress.c +++ b/tools/testing/selftests/mm/uffd-stress.c @@ -448,12 +448,6 @@ int main(int argc, char **argv) parse_test_type_arg(argv[1]); bytes = atol(argv[2]) * 1024 * 1024;
- if (test_type == TEST_HUGETLB && - get_free_hugepages() < bytes / page_size) { - printf("skip: Skipping userfaultfd... not enough hugepages\n"); - return KSFT_SKIP; - } - nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); if (nr_cpus > 32) { /* Don't let calculation below go to zero. */ @@ -464,6 +458,17 @@ int main(int argc, char **argv) nr_parallel = nr_cpus; }
+ /* + * src and dst each require bytes / page_size number of hugepages. + * Ensure nr_parallel - 1 hugepages on top of that to account + * for racy extra reservation of hugepages. + */ + if (test_type == TEST_HUGETLB && + get_free_hugepages() < 2 * (bytes / page_size) + nr_parallel - 1) { + printf("skip: Skipping userfaultfd... not enough hugepages\n"); + return KSFT_SKIP; + } + nr_pages_per_cpu = bytes / page_size / nr_parallel; if (!nr_pages_per_cpu) { _err("pages_per_cpu = 0, cannot test (%lu / %lu / %lu)",