3 files changed, 20 insertions, 2 deletions

diff --git a/mm/internal.h b/mm/internal.h
index a25424a24e0c..e067984bafa0 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -201,7 +201,12 @@ static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
                 return 0;
 
         if (!TestSetPageMlocked(page)) {
-                mod_zone_page_state(page_zone(page), NR_MLOCK,
+                /*
+                 * We use the irq-unsafe __mod_zone_page_stat because this
+                 * counter is not modified from interrupt context, and the pte
+                 * lock is held(spinlock), which implies preemption disabled.
+                 */
+                __mod_zone_page_state(page_zone(page), NR_MLOCK,
                                     hpage_nr_pages(page));
                 count_vm_event(UNEVICTABLE_PGMLOCKED);
         }
diff --git a/mm/rmap.c b/mm/rmap.c
index 8754e1fa83b6..4644e10248f0 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -988,6 +988,12 @@ void do_page_add_anon_rmap(struct page *page,
 {
         int first = atomic_inc_and_test(&page->_mapcount);
         if (first) {
+                /*
+                 * We use the irq-unsafe __{inc|mod}_zone_page_stat because
+                 * these counters are not modified in interrupt context, and
+                 * pte lock(a spinlock) is held, which implies preemption
+                 * disabled.
+                 */
                 if (PageTransHuge(page))
                         __inc_zone_page_state(page,
                                               NR_ANON_TRANSPARENT_HUGEPAGES);
@@ -1079,6 +1085,11 @@ void page_remove_rmap(struct page *page)
         /*
          * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED
          * and not charged by memcg for now.
+         *
+         * We use the irq-unsafe __{inc|mod}_zone_page_stat because
+         * these counters are not modified in interrupt context, and
+         * these counters are not modified in interrupt context, and
+         * pte lock(a spinlock) is held, which implies preemption disabled.
          */
         if (unlikely(PageHuge(page)))
                 goto out;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 376bd2d21482..b37bd49bfd55 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -207,7 +207,9 @@ void set_pgdat_percpu_threshold(pg_data_t *pgdat,
 }
 
 /*
- * For use when we know that interrupts are disabled.
+ * For use when we know that interrupts are disabled,
+ * or when we know that preemption is disabled and that
+ * particular counter cannot be updated from interrupt context.
  */
 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
                                 int delta)