mm: remove free_page_mlock

We should not be seeing non-0 unevictable_pgs_mlockfreed any longer.  So
remove free_page_mlock() from the page freeing paths: __PG_MLOCKED is
already in PAGE_FLAGS_CHECK_AT_FREE, so free_pages_check() will now be
checking it, reporting "BUG: Bad page state" if it's ever found set.
Comment UNEVICTABLE_MLOCKFREED and unevictable_pgs_mlockfreed always 0.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 17 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 00750bc08a3a..dbb53866c3aa 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -598,17 +598,6 @@ out:
         zone->free_area[order].nr_free++;
 }
 
-/*
- * free_page_mlock() -- clean up attempts to free and mlocked() page.
- * Page should not be on lru, so no need to fix that up.
- * free_pages_check() will verify...
- */
-static inline void free_page_mlock(struct page *page)
-{
-        __dec_zone_page_state(page, NR_MLOCK);
-        __count_vm_event(UNEVICTABLE_MLOCKFREED);
-}
-
 static inline int free_pages_check(struct page *page)
 {
         if (unlikely(page_mapcount(page) |
@@ -728,15 +717,12 @@ static bool free_pages_prepare(struct page *page, unsigned int order)
 static void __free_pages_ok(struct page *page, unsigned int order)
 {
         unsigned long flags;
-        int wasMlocked = __TestClearPageMlocked(page);
         int migratetype;
 
         if (!free_pages_prepare(page, order))
                 return;
 
         local_irq_save(flags);
-        if (unlikely(wasMlocked))
-                free_page_mlock(page);
         __count_vm_events(PGFREE, 1 << order);
         migratetype = get_pageblock_migratetype(page);
         set_freepage_migratetype(page, migratetype);
@@ -1310,7 +1296,6 @@ void free_hot_cold_page(struct page *page, int cold)
         struct per_cpu_pages *pcp;
         unsigned long flags;
         int migratetype;
-        int wasMlocked = __TestClearPageMlocked(page);
 
         if (!free_pages_prepare(page, 0))
                 return;
@@ -1318,8 +1303,6 @@ void free_hot_cold_page(struct page *page, int cold)
         migratetype = get_pageblock_migratetype(page);
         set_freepage_migratetype(page, migratetype);
         local_irq_save(flags);
-        if (unlikely(wasMlocked))
-                free_page_mlock(page);
         __count_vm_event(PGFREE);
 
         /*