tests/heapshrink: allocate enough to expand heap

This test failed on aarch64 with 512M pages, because allocating
32M is possible without expanding heap. Make sure we allocate
enough, so that free has something to shrink.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Eric B Munson <emunson@mgebm.net>

tests/heapshrink.c

@@ -29,14 +29,14 @@
  * the mapping page size is larger than this.
  */
 #define MIN_PAGE_SIZE 65536
-
-#define	SIZE	(32 * 1024 * 1024)
+#define MAX(a, b) a > b ? a : b
 
 int main(int argc, char **argv)
 {
 	int is_huge, have_env, shrink_ok, have_helper;
 	unsigned long long mapping_size;
 	void *p;
+	long size = MAX(32*1024*1024, kernel_default_hugepage_size());
 
 	test_init(argc, argv);
 
@@ -45,15 +45,15 @@ int main(int argc, char **argv)
 	p = getenv("LD_PRELOAD");
 	have_helper = p != NULL && strstr(p, "heapshrink") != NULL;
 
-	p = malloc(SIZE);
+	p = malloc(size);
 	if (!p) {
 		if (shrink_ok && have_helper) {
 			/* Hitting unexpected behavior in malloc() */
 			PASS_INCONCLUSIVE();
 		} else
-			FAIL("malloc(%d) failed\n", SIZE);
+			FAIL("malloc(%ld) failed\n", size);
 	}
-	memset(p, 0, SIZE);
+	memset(p, 0, size);
 	mapping_size = get_mapping_page_size(p);
 	is_huge = (mapping_size > MIN_PAGE_SIZE);
 	if (have_env && !is_huge) {
@@ -67,7 +67,7 @@ int main(int argc, char **argv)
 		FAIL("Heap unexpectedly on hugepages");
 
 	free(p);
-	mapping_size = get_mapping_page_size(p+SIZE-1);
+	mapping_size = get_mapping_page_size(p+size-1);
 	if (shrink_ok && mapping_size > MIN_PAGE_SIZE)
 		FAIL("Heap did not shrink");
 	PASS();