[v17,15/21] mm/thp: add tail pages into lru anyway in split_huge_page()
diff mbox series

Message ID 1595681998-19193-16-git-send-email-alex.shi@linux.alibaba.com
State New
Headers show
Series
  • per memcg lru lock
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Commit Message

Alex Shi July 25, 2020, 12:59 p.m. UTC
Split_huge_page() must start with PageLRU(head), and we are holding the
lru_lock here. If the head was cleared lru bit unexpected, tracking it.

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
---
 mm/huge_memory.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

Patch
diff mbox series

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d866b6e43434..28538444197b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2348,15 +2348,19 @@  static void lru_add_page_tail(struct page *head, struct page *page_tail,
 	VM_BUG_ON_PAGE(PageLRU(page_tail), head);
 	lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
 
-	if (!list)
-		SetPageLRU(page_tail);
-
-	if (likely(PageLRU(head)))
-		list_add_tail(&page_tail->lru, &head->lru);
-	else if (list) {
+	if (list) {
 		/* page reclaim is reclaiming a huge page */
 		get_page(page_tail);
 		list_add_tail(&page_tail->lru, list);
+	} else {
+		/*
+		 * Split start from PageLRU(head), and we are holding the
+		 * lru_lock.
+		 * Do a warning if the head's lru bit was cleared unexpected.
+		 */
+		VM_WARN_ON(!PageLRU(head));
+		SetPageLRU(page_tail);
+		list_add_tail(&page_tail->lru, &head->lru);
 	}
 }