[PATCH v4 49/55] selftests/mm: uffd-stress: use hugetlb_save and alloc huge pages

[Mike Rapoport <rppt@kernel.org>]

From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

uffd-stress skips HugeTLB tests if there are no free huge pages prepared
by a wrapper script.

Add setup of HugeTLB pages to the test and make sure that the original
settings are restored on the test exit.

Tested-by: Luiz Capitulino <luizcap@redhat.com>
Tested-by: Sarthak Sharma <sarthak.sharma@arm.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 tools/testing/selftests/mm/uffd-stress.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index 7c719d789249..43cc79590136 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -480,9 +480,12 @@ int main(int argc, char **argv)
 	 * Ensure nr_parallel - 1 hugepages on top of that to account
 	 * for racy extra reservation of hugepages.
 	 */
-	if (gopts->test_type == TEST_HUGETLB &&
-	   hugetlb_free_default_pages() < 2 * (bytes / gopts->page_size) + gopts->nr_parallel - 1)
-		ksft_exit_skip("Skipping userfaultfd... not enough hugepages\n");
+	if (gopts->test_type == TEST_HUGETLB) {
+		unsigned long nr = 2 * (bytes / gopts->page_size) + gopts->nr_parallel - 1;
+
+		if (!hugetlb_setup_default(nr))
+			ksft_exit_skip("Skipping userfaultfd... not enough hugepages\n");
+	}
 
 	gopts->nr_pages_per_cpu = bytes / gopts->page_size / gopts->nr_parallel;
 	if (!gopts->nr_pages_per_cpu) {
-- 
2.53.0