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Date:   Fri,  8 May 2020 14:22:13 -0700
Message-Id: <20200508212215.181307-1-shakeelb@google.com>
Mime-Version: 1.0
Subject: [PATCH 1/3] mm: swap: fix vmstats for huge pages
From:   Shakeel Butt <shakeelb@google.com>
To:     Mel Gorman <mgorman@suse.de>, Johannes Weiner <hannes@cmpxchg.org>,
        Roman Gushchin <guro@fb.com>, Michal Hocko <mhocko@kernel.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Yafang Shao <laoar.shao@gmail.com>, linux-mm@kvack.org,
        cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
        Shakeel Butt <shakeelb@google.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Many of the callbacks called by pagevec_lru_move_fn() do not correctly
update the vmstats for huge pages. Fix that. Also __pagevec_lru_add_fn()
use the irq-unsafe alternative to update the stat as the irqs are
already disabled.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
---
 mm/swap.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index a37bd7b202ac..3dbef6517cac 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -225,7 +225,7 @@ static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec,
 		del_page_from_lru_list(page, lruvec, page_lru(page));
 		ClearPageActive(page);
 		add_page_to_lru_list_tail(page, lruvec, page_lru(page));
-		(*pgmoved)++;
+		(*pgmoved) += hpage_nr_pages(page);
 	}
 }
 
@@ -285,7 +285,7 @@ static void __activate_page(struct page *page, struct lruvec *lruvec,
 		add_page_to_lru_list(page, lruvec, lru);
 		trace_mm_lru_activate(page);
 
-		__count_vm_event(PGACTIVATE);
+		__count_vm_events(PGACTIVATE, hpage_nr_pages(page));
 		update_page_reclaim_stat(lruvec, file, 1);
 	}
 }
@@ -503,6 +503,7 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec,
 {
 	int lru, file;
 	bool active;
+	int nr_pages = hpage_nr_pages(page);
 
 	if (!PageLRU(page))
 		return;
@@ -536,11 +537,11 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec,
 		 * We moves tha page into tail of inactive.
 		 */
 		add_page_to_lru_list_tail(page, lruvec, lru);
-		__count_vm_event(PGROTATED);
+		__count_vm_events(PGROTATED, nr_pages);
 	}
 
 	if (active)
-		__count_vm_event(PGDEACTIVATE);
+		__count_vm_events(PGDEACTIVATE, nr_pages);
 	update_page_reclaim_stat(lruvec, file, 0);
 }
 
@@ -929,6 +930,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
 {
 	enum lru_list lru;
 	int was_unevictable = TestClearPageUnevictable(page);
+	int nr_pages = hpage_nr_pages(page);
 
 	VM_BUG_ON_PAGE(PageLRU(page), page);
 
@@ -966,13 +968,13 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
 		update_page_reclaim_stat(lruvec, page_is_file_lru(page),
 					 PageActive(page));
 		if (was_unevictable)
-			count_vm_event(UNEVICTABLE_PGRESCUED);
+			__count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages);
 	} else {
 		lru = LRU_UNEVICTABLE;
 		ClearPageActive(page);
 		SetPageUnevictable(page);
 		if (!was_unevictable)
-			count_vm_event(UNEVICTABLE_PGCULLED);
+			__count_vm_events(UNEVICTABLE_PGCULLED, nr_pages);
 	}
 
 	add_page_to_lru_list(page, lruvec, lru);
-- 
2.26.2.645.ge9eca65c58-goog