mm/swap_slots.c: assign|reset cache slot by value directly

Currently we use a tmp pointer, pentry, to transfer and reset swap cache
slot, which is a little redundant.  Swap cache slot stores the entry value
directly, assign and reset it by value would be straight forward.

Also this patch merges the else and if, since this is the only case we
refill and repeat swap cache.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20200311055352.50574-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index 63a7b4563a57ee3367b8963b1219323a4d3b28c9..0975adc722532e5e6ddfee770a3ef4848b093866 100644 (file)
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -309,7 +309,7 @@ direct_free:
 
 swp_entry_t get_swap_page(struct page *page)
 {
-       swp_entry_t entry, *pentry;
+       swp_entry_t entry;
        struct swap_slots_cache *cache;
 
        entry.val = 0;
@@ -336,13 +336,11 @@ swp_entry_t get_swap_page(struct page *page)
                if (cache->slots) {
 repeat:
                        if (cache->nr) {
-                               pentry = &cache->slots[cache->cur++];
-                               entry = *pentry;
-                               pentry->val = 0;
+                               entry = cache->slots[cache->cur];
+                               cache->slots[cache->cur++].val = 0;
                                cache->nr--;
-                       } else {
-                               if (refill_swap_slots_cache(cache))
-                                       goto repeat;
+                       } else if (refill_swap_slots_cache(cache)) {
+                               goto repeat;
                        }
                }
                mutex_unlock(&cache->alloc_lock);