mm/swapfile.c: use prandom_u32_max()

To improve the code readability and take advantage of the common
implementation.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/r/20200512081013.520201-1-ying.huang@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 2aa2723..18dfccb 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3209,7 +3209,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
                 * select a random position to start with to help wear leveling
                 * SSD
                 */
-               p->cluster_next = 1 + (prandom_u32() % p->highest_bit);
+               p->cluster_next = 1 + prandom_u32_max(p->highest_bit);
                nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
 
                cluster_info = kvcalloc(nr_cluster, sizeof(*cluster_info),