From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/swapfile.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/mm/swapfile.c~mm-swap-use-memset-to-fill-the-swap_map-with-swap_has_cache +++ a/mm/swapfile.c @@ -975,8 +975,7 @@ static int swap_alloc_cluster(struct swa { 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 swa 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); _