selftests/mm: merge default_huge_page_size() into one

There're already 3 same definitions of the three functions.  Move it into
vm_util.[ch].

Link: https://lkml.kernel.org/r/20230412164223.328134-1-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/selftests/mm/hugetlb-madvise.c

@@ -18,6 +18,7 @@
 #include <unistd.h>
 #include <sys/mman.h>
 #include <fcntl.h>
+#include "vm_util.h"
 
 #define MIN_FREE_PAGES	20
 #define NR_HUGE_PAGES	10	/* common number of pages to map/allocate */
@@ -35,30 +36,6 @@
 unsigned long huge_page_size;
 unsigned long base_page_size;
 
-/*
- * default_huge_page_size copied from mlock2-tests.c
- */
-unsigned long default_huge_page_size(void)
-{
-	unsigned long hps = 0;
-	char *line = NULL;
-	size_t linelen = 0;
-	FILE *f = fopen("/proc/meminfo", "r");
-
-	if (!f)
-		return 0;
-	while (getline(&line, &linelen, f) > 0) {
-		if (sscanf(line, "Hugepagesize:       %lu kB", &hps) == 1) {
-			hps <<= 10;
-			break;
-		}
-	}
-
-	free(line);
-	fclose(f);
-	return hps;
-}
-
 unsigned long get_free_hugepages(void)
 {
 	unsigned long fhp = 0;

tools/testing/selftests/mm/thuge-gen.c

@@ -24,6 +24,7 @@
 #include <unistd.h>
 #include <stdarg.h>
 #include <string.h>
+#include "vm_util.h"
 
 #define err(x) perror(x), exit(1)
 
@@ -74,24 +75,6 @@ void find_pagesizes(void)
 	globfree(&g);
 }
 
-unsigned long default_huge_page_size(void)
-{
-	unsigned long hps = 0;
-	char *line = NULL;
-	size_t linelen = 0;
-	FILE *f = fopen("/proc/meminfo", "r");
-	if (!f)
-		return 0;
-	while (getline(&line, &linelen, f) > 0) {
-		if (sscanf(line, "Hugepagesize:       %lu kB", &hps) == 1) {
-			hps <<= 10;
-			break;
-		}
-	}
-	free(line);
-	return hps;
-}
-
 void show(unsigned long ps)
 {
 	char buf[100];

tools/testing/selftests/mm/userfaultfd.c

@@ -1703,30 +1703,6 @@ static int userfaultfd_stress(void)
 		|| userfaultfd_events_test() || userfaultfd_minor_test();
 }
 
-/*
- * Copied from mlock2-tests.c
- */
-unsigned long default_huge_page_size(void)
-{
-	unsigned long hps = 0;
-	char *line = NULL;
-	size_t linelen = 0;
-	FILE *f = fopen("/proc/meminfo", "r");
-
-	if (!f)
-		return 0;
-	while (getline(&line, &linelen, f) > 0) {
-		if (sscanf(line, "Hugepagesize:       %lu kB", &hps) == 1) {
-			hps <<= 10;
-			break;
-		}
-	}
-
-	free(line);
-	fclose(f);
-	return hps;
-}
-
 static void set_test_type(const char *type)
 {
 	if (!strcmp(type, "anon")) {

tools/testing/selftests/mm/vm_util.c

@@ -180,3 +180,24 @@ int64_t allocate_transhuge(void *ptr, int pagemap_fd)
 
 	return -1;
 }
+
+unsigned long default_huge_page_size(void)
+{
+	unsigned long hps = 0;
+	char *line = NULL;
+	size_t linelen = 0;
+	FILE *f = fopen("/proc/meminfo", "r");
+
+	if (!f)
+		return 0;
+	while (getline(&line, &linelen, f) > 0) {
+		if (sscanf(line, "Hugepagesize:       %lu kB", &hps) == 1) {
+			hps <<= 10;
+			break;
+		}
+	}
+
+	free(line);
+	fclose(f);
+	return hps;
+}

tools/testing/selftests/mm/vm_util.h

@@ -35,6 +35,7 @@ bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size);
 bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size);
 bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size);
 int64_t allocate_transhuge(void *ptr, int pagemap_fd);
+unsigned long default_huge_page_size(void);
 
 /*
  * On ppc64 this will only work with radix 2M hugepage size