linux-kernel - [PATCH 08/13] mm: rename page_off_lru() to __clear_page_lru

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Message-Id: <20200918030051.650890-9-yuzhao@google.com>
Date:   Thu, 17 Sep 2020 21:00:46 -0600
From:   Yu Zhao <yuzhao@...gle.com>
To:     Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...nel.org>
Cc:     Alex Shi <alex.shi@...ux.alibaba.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ingo Molnar <mingo@...hat.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Vladimir Davydov <vdavydov.dev@...il.com>,
        Roman Gushchin <guro@...com>,
        Shakeel Butt <shakeelb@...gle.com>,
        Chris Down <chris@...isdown.name>,
        Yafang Shao <laoar.shao@...il.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Huang Ying <ying.huang@...el.com>,
        Pankaj Gupta <pankaj.gupta.linux@...il.com>,
        Matthew Wilcox <willy@...radead.org>,
        Konstantin Khlebnikov <koct9i@...il.com>,
        Minchan Kim <minchan@...nel.org>,
        Jaewon Kim <jaewon31.kim@...sung.com>, cgroups@...r.kernel.org,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Yu Zhao <yuzhao@...gle.com>
Subject: [PATCH 08/13] mm: rename page_off_lru() to __clear_page_lru_flags()

Rename the function according to what it really does. And make it
return void since the return value is not needed anymore.

If PageActive() and PageUnevictable() are both true, refuse to clear
either and leave them to bad_page().

Signed-off-by: Yu Zhao <yuzhao@...gle.com>
---
 include/linux/mm_inline.h | 29 ++++++++++-------------------
 mm/swap.c                 |  4 ++--
 mm/vmscan.c               |  2 +-
 3 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 03796021f0fe..ef3fd79222e5 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -61,28 +61,19 @@ static inline enum lru_list page_lru_base_type(struct page *page)
 }
 
 /**
- * page_off_lru - which LRU list was page on? clearing its lru flags.
- * @page: the page to test
- *
- * Returns the LRU list a page was on, as an index into the array of LRU
- * lists; and clears its Unevictable or Active flags, ready for freeing.
+ * __clear_page_lru_flags - clear page lru flags before releasing a page
+ * @page: the page that was on lru and now has a zero reference
  */
-static __always_inline enum lru_list page_off_lru(struct page *page)
+static __always_inline void __clear_page_lru_flags(struct page *page)
 {
-	enum lru_list lru;
-
 	__ClearPageLRU(page);
-	if (PageUnevictable(page)) {
-		__ClearPageUnevictable(page);
-		lru = LRU_UNEVICTABLE;
-	} else {
-		lru = page_lru_base_type(page);
-		if (PageActive(page)) {
-			__ClearPageActive(page);
-			lru += LRU_ACTIVE;
-		}
-	}
-	return lru;
+
+	/* this shouldn't happen, so leave the flags to bad_page() */
+	if (PageActive(page) && PageUnevictable(page))
+		return;
+
+	__ClearPageActive(page);
+	__ClearPageUnevictable(page);
 }
 
 /**
diff --git a/mm/swap.c b/mm/swap.c
index 8bbeabc582c1..b252f3593c57 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -87,7 +87,7 @@ static void __page_cache_release(struct page *page)
 		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 		VM_BUG_ON_PAGE(!PageLRU(page), page);
 		del_page_from_lru_list(page, lruvec);
-		page_off_lru(page);
+		__clear_page_lru_flags(page);
 		spin_unlock_irqrestore(&pgdat->lru_lock, flags);
 	}
 }
@@ -887,7 +887,7 @@ void release_pages(struct page **pages, int nr)
 			lruvec = mem_cgroup_page_lruvec(page, locked_pgdat);
 			VM_BUG_ON_PAGE(!PageLRU(page), page);
 			del_page_from_lru_list(page, lruvec);
-			page_off_lru(page);
+			__clear_page_lru_flags(page);
 		}
 
 		list_add(&page->lru, &pages_to_free);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 47a4e8ba150f..d93033407200 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1862,7 +1862,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
 
 		if (put_page_testzero(page)) {
 			del_page_from_lru_list(page, lruvec);
-			page_off_lru(page);
+			__clear_page_lru_flags(page);
 
 			if (unlikely(PageCompound(page))) {
 				spin_unlock_irq(&pgdat->lru_lock);
-- 
2.28.0.681.g6f77f65b4e-goog