mm/migration: use helper macro min in do_pages_stat

We could use helper macro min to help set the chunk_nr to simplify the
code.

Link: https://lkml.kernel.org/r/20220318111709.60311-7-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/migrate.c b/mm/migrate.c
index e73e1bfa874b37478c9774513ccc43f109ee46fa..02448b618c6b2beb68c46c75a8bc57e63f2c7b78 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1842,16 +1842,12 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
                         const void __user * __user *pages,
                         int __user *status)
 {
-#define DO_PAGES_STAT_CHUNK_NR 16
+#define DO_PAGES_STAT_CHUNK_NR 16UL
        const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR];
        int chunk_status[DO_PAGES_STAT_CHUNK_NR];
 
        while (nr_pages) {
-               unsigned long chunk_nr;
-
-               chunk_nr = nr_pages;
-               if (chunk_nr > DO_PAGES_STAT_CHUNK_NR)
-                       chunk_nr = DO_PAGES_STAT_CHUNK_NR;
+               unsigned long chunk_nr = min(nr_pages, DO_PAGES_STAT_CHUNK_NR);
 
                if (in_compat_syscall()) {
                        if (get_compat_pages_array(chunk_pages, pages,