mm/page_alloc.c: use list_{first,last}_entry instead of list_entry

To make the intention clearer, use list_{first,last}_entry instead of
list_entry.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 12 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fbff97d7b298..b9747aa0fb59 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -805,7 +805,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
                 do {
                         int mt; /* migratetype of the to-be-freed page */
 
-                        page = list_entry(list->prev, struct page, lru);
+                        page = list_last_entry(list, struct page, lru);
                         /* must delete as __free_one_page list manipulates */
                         list_del(&page->lru);
 
@@ -1410,11 +1410,10 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
         /* Find a page of the appropriate size in the preferred list */
         for (current_order = order; current_order < MAX_ORDER; ++current_order) {
                 area = &(zone->free_area[current_order]);
-                if (list_empty(&area->free_list[migratetype]))
-                        continue;
-
-                page = list_entry(area->free_list[migratetype].next,
+                page = list_first_entry_or_null(&area->free_list[migratetype],
                                                         struct page, lru);
+                if (!page)
+                        continue;
                 list_del(&page->lru);
                 rmv_page_order(page);
                 area->nr_free--;
@@ -1693,12 +1692,12 @@ static void unreserve_highatomic_pageblock(const struct alloc_context *ac)
                 for (order = 0; order < MAX_ORDER; order++) {
                         struct free_area *area = &(zone->free_area[order]);
 
-                        if (list_empty(&area->free_list[MIGRATE_HIGHATOMIC]))
+                        page = list_first_entry_or_null(
+                                        &area->free_list[MIGRATE_HIGHATOMIC],
+                                        struct page, lru);
+                        if (!page)
                                 continue;
 
-                        page = list_entry(area->free_list[MIGRATE_HIGHATOMIC].next,
-                                                struct page, lru);
-
                         /*
                          * It should never happen but changes to locking could
                          * inadvertently allow a per-cpu drain to add pages
@@ -1746,7 +1745,7 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
                 if (fallback_mt == -1)
                         continue;
 
-                page = list_entry(area->free_list[fallback_mt].next,
+                page = list_first_entry(&area->free_list[fallback_mt],
                                                 struct page, lru);
                 if (can_steal)
                         steal_suitable_fallback(zone, page, start_migratetype);
@@ -2205,9 +2204,9 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
                 }
 
                 if (cold)
-                        page = list_entry(list->prev, struct page, lru);
+                        page = list_last_entry(list, struct page, lru);
                 else
-                        page = list_entry(list->next, struct page, lru);
+                        page = list_first_entry(list, struct page, lru);
 
                 list_del(&page->lru);
                 pcp->count--;