[PATCH v3 39/54] selftests/mm: hugetlb-mmap: add setup of HugeTLB pages

[Mike Rapoport <rppt@kernel.org>]

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

hugetlb-mmap test fails 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.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 tools/testing/selftests/mm/hugetlb-mmap.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/mm/hugetlb-mmap.c b/tools/testing/selftests/mm/hugetlb-mmap.c
index 031085cb7d17..f12fc288ef4f 100644
--- a/tools/testing/selftests/mm/hugetlb-mmap.c
+++ b/tools/testing/selftests/mm/hugetlb-mmap.c
@@ -109,16 +109,16 @@ int main(int argc, char **argv)
 {
 	size_t hugepage_size;
 	size_t length = LENGTH;
-	int shift = 0;
+	int shift = 0, nr;
 
 	ksft_print_header();
-	ksft_set_plan(2);
 
 	if (argc > 1)
 		length = atol(argv[1]) << 20;
 	if (argc > 2)
 		shift = atoi(argv[2]);
 
+	hugetlb_save_settings();
 	if (shift) {
 		hugepage_size = (1 << shift);
 		ksft_print_msg("%u kB hugepages\n", 1 << (shift - 10));
@@ -128,9 +128,14 @@ int main(int argc, char **argv)
 	}
 
 	/* munmap with fail if the length is not page aligned */
-	if (hugepage_size > length)
-		length = hugepage_size;
+	length = (length + hugepage_size - 1) & ~(hugepage_size - 1);
+	nr = length / hugepage_size;
+
+	hugetlb_set_nr_pages(hugepage_size, nr);
+	if (hugetlb_free_pages(hugepage_size) < nr)
+		ksft_exit_skip("Not enough %lu Kb pages\n", hugepage_size >> 10);
 
+	ksft_set_plan(2);
 	ksft_print_msg("Mapping %lu Mbytes\n", (unsigned long)length >> 20);
 
 	test_anon_mmap(length, shift);
-- 
2.53.0