mm/swapfile.c: use memset to fill the swap_map with SWAP_HAS_CACHE

We could use helper memset to fill the swap_map with SWAP_HAS_CACHE instead
of a direct loop here to simplify the code. Also we can remove the local
variable i and map this way.

Link: https://lkml.kernel.org/r/20200921122224.7139-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 83df467e1135ccd88670836c724a40e3a825ca53..1c0a829f7311e8fc2e9adc01d93063e543bce1c6 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -975,8 +975,7 @@ static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot)
 {
        unsigned long idx;
        struct swap_cluster_info *ci;
-       unsigned long offset, i;
-       unsigned char *map;
+       unsigned long offset;
 
        /*
         * Should not even be attempting cluster allocations when huge
@@ -996,9 +995,7 @@ static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot)
        alloc_cluster(si, idx);
        cluster_set_count_flag(ci, SWAPFILE_CLUSTER, CLUSTER_FLAG_HUGE);
 
-       map = si->swap_map + offset;
-       for (i = 0; i < SWAPFILE_CLUSTER; i++)
-               map[i] = SWAP_HAS_CACHE;
+       memset(si->swap_map + offset, SWAP_HAS_CACHE, SWAPFILE_CLUSTER);
        unlock_cluster(ci);
        swap_range_alloc(si, offset, SWAPFILE_CLUSTER);
        *slot = swp_entry(si->type, offset);