lib/test_vmalloc.c: add parameter use_huge for fix_size_alloc_test

Add a parameter `use_huge' for fix_size_alloc_test(), which can be used to
test allocation vie vmalloc_huge for both functionality and performance.

Link: https://lkml.kernel.org/r/20221212055657.698420-1-panqinglin2020@iscas.ac.cnSigned-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/test_vmalloc.c

@@ -38,6 +38,9 @@ __param(int, test_loop_count, 1000000,
 __param(int, nr_pages, 0,
 	"Set number of pages for fix_size_alloc_test(default: 1)");
 
+__param(bool, use_huge, false,
+	"Use vmalloc_huge in fix_size_alloc_test");
+
 __param(int, run_test_mask, INT_MAX,
 	"Set tests specified in the mask.\n\n"
 		"\t\tid: 1,    name: fix_size_alloc_test\n"
@@ -264,7 +267,10 @@ static int fix_size_alloc_test(void)
 	int i;
 
 	for (i = 0; i < test_loop_count; i++) {
-		ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE);
+		if (use_huge)
+			ptr = vmalloc_huge((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE, GFP_KERNEL);
+		else
+			ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE);
 
 		if (!ptr)
 			return -1;