selftests/mm: use generic read_sysfs in thuge-gen test

As generic read_sysfs is available in vm_utils, let's use is in thuge-gen
test.

Link: https://lkml.kernel.org/r/20250611100106.1331197-1-pulehui@huaweicloud.com
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/thuge-gen.c b/tools/testing/selftests/mm/thuge-gen.c
index 95b6f043a3cbd3a66655e899e9acdfc4ef50ec9e..8e2b08dc5762072b17f0d05133dbe85552c1e121 100644 (file)
--- a/tools/testing/selftests/mm/thuge-gen.c
+++ b/tools/testing/selftests/mm/thuge-gen.c
@@ -77,40 +77,20 @@ void show(unsigned long ps)
        system(buf);
 }
 
-unsigned long thuge_read_sysfs(int warn, char *fmt, ...)
+unsigned long read_free(unsigned long ps)
 {
-       char *line = NULL;
-       size_t linelen = 0;
-       char buf[100];
-       FILE *f;
-       va_list ap;
        unsigned long val = 0;
+       char buf[100];
 
-       va_start(ap, fmt);
-       vsnprintf(buf, sizeof buf, fmt, ap);
-       va_end(ap);
+       snprintf(buf, sizeof(buf),
+                "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages",
+                ps >> 10);
+       if (read_sysfs(buf, &val) && ps != getpagesize())
+               ksft_print_msg("missing %s\n", buf);
 
-       f = fopen(buf, "r");
-       if (!f) {
-               if (warn)
-                       ksft_print_msg("missing %s\n", buf);
-               return 0;
-       }
-       if (getline(&line, &linelen, f) > 0) {
-               sscanf(line, "%lu", &val);
-       }
-       fclose(f);
-       free(line);
        return val;
 }
 
-unsigned long read_free(unsigned long ps)
-{
-       return thuge_read_sysfs(ps != getpagesize(),
-                         "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages",
-                         ps >> 10);
-}
-
 void test_mmap(unsigned long size, unsigned flags)
 {
        char *map;
@@ -173,6 +153,7 @@ void test_shmget(unsigned long size, unsigned flags)
 void find_pagesizes(void)
 {
        unsigned long largest = getpagesize();
+       unsigned long shmmax_val = 0;
        int i;
        glob_t g;
 
@@ -195,7 +176,8 @@ void find_pagesizes(void)
        }
        globfree(&g);
 
-       if (thuge_read_sysfs(0, "/proc/sys/kernel/shmmax") < NUM_PAGES * largest)
+       read_sysfs("/proc/sys/kernel/shmmax", &shmmax_val);
+       if (shmmax_val < NUM_PAGES * largest)
                ksft_exit_fail_msg("Please do echo %lu > /proc/sys/kernel/shmmax",
                                   largest * NUM_PAGES);