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From:   Muchun Song <songmuchun@bytedance.com>
To:     akpm@linux-foundation.org, zi.yan@cs.rutgers.edu,
        kirill.shutemov@linux.intel.com
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH 2/2] mm: fix missing cache flush for all tail pages of THP
Date:   Fri, 21 Jan 2022 16:13:45 +0800
Message-Id: <20220121081345.80320-2-songmuchun@bytedance.com>
In-Reply-To: <20220121081345.80320-1-songmuchun@bytedance.com>
References: <20220121081345.80320-1-songmuchun@bytedance.com>
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The D-cache maintenance inside move_to_new_page() only consider one page,
there is still D-cache maintenance issue for tail pages of THP. Fix this
by using flush_dcache_folio().

Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/migrate.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index c9296d63878d..daf2b3508670 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -934,8 +934,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
 			page->mapping = NULL;
 
 		if (likely(!is_zone_device_page(newpage)))
-			flush_dcache_page(newpage);
-
+			flush_dcache_folio(page_folio(newpage));
 	}
 out:
 	return rc;
-- 
2.11.0