[PATCH 39/53] selftests/mm: hugetlb-mremap: add setup of HugeTLB pages

[Mike Rapoport <rppt@kernel.org>]

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

hugetlb-mremap 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-mremap.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/hugetlb-mremap.c b/tools/testing/selftests/mm/hugetlb-mremap.c
index 1c87c39780c5..09241a279ec2 100644
--- a/tools/testing/selftests/mm/hugetlb-mremap.c
+++ b/tools/testing/selftests/mm/hugetlb-mremap.c
@@ -26,6 +26,7 @@
 #include <stdbool.h>
 #include "kselftest.h"
 #include "vm_util.h"
+#include "hugepage_settings.h"
 
 #define DEFAULT_LENGTH_MB 10UL
 #define MB_TO_BYTES(x) (x * 1024 * 1024)
@@ -108,8 +109,9 @@ static void register_region_with_uffd(char *addr, size_t len)
 
 int main(int argc, char *argv[])
 {
+	unsigned long hugepage_size;
+	int ret = 0, fd, nr;
 	size_t length = 0;
-	int ret = 0, fd;
 
 	ksft_print_header();
 	ksft_set_plan(1);
@@ -125,7 +127,14 @@ int main(int argc, char *argv[])
 	else
 		length = DEFAULT_LENGTH_MB;
 
+	hugepage_size = default_huge_page_size();
 	length = MB_TO_BYTES(length);
+	length = (length + hugepage_size) & ~(hugepage_size - 1);
+	nr = length / hugepage_size;
+
+	if (!hugetlb_setup_default(nr))
+		ksft_exit_skip("Not enough huge pages\n");
+
 	fd = memfd_create(argv[0], MFD_HUGETLB);
 	if (fd < 0)
 		ksft_exit_fail_msg("Open failed: %s\n", strerror(errno));
-- 
2.53.0