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From:   Minchan Kim <minchan@kernel.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     LKML <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>,
        Michal Hocko <mhocko@suse.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Tim Murray <timmurray@google.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Suren Baghdasaryan <surenb@google.com>,
        Daniel Colascione <dancol@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        Sonny Rao <sonnyrao@google.com>,
        Brian Geffon <bgeffon@google.com>,
        Minchan Kim <minchan@kernel.org>
Subject: [RFC 2/7] mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM
Date:   Mon, 20 May 2019 12:52:49 +0900
Message-Id: <20190520035254.57579-3-minchan@kernel.org>
In-Reply-To: <20190520035254.57579-1-minchan@kernel.org>
References: <20190520035254.57579-1-minchan@kernel.org>
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The local variable references in shrink_page_list is PAGEREF_RECLAIM_CLEAN
as default. It is for preventing to reclaim dirty pages when CMA try to
migrate pages. Strictly speaking, we don't need it because CMA didn't allow
to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.

Moreover, it has a problem to prevent anonymous pages's swap out even
though force_reclaim = true in shrink_page_list on upcoming patch.
So this patch makes references's default value to PAGEREF_RECLAIM and
rename force_reclaim with skip_reference_check to make it more clear.

This is a preparatory work for next patch.

Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 mm/vmscan.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index d9c3e873eca6..a28e5d17b495 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1102,7 +1102,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 				      struct scan_control *sc,
 				      enum ttu_flags ttu_flags,
 				      struct reclaim_stat *stat,
-				      bool force_reclaim)
+				      bool skip_reference_check)
 {
 	LIST_HEAD(ret_pages);
 	LIST_HEAD(free_pages);
@@ -1116,7 +1116,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		struct address_space *mapping;
 		struct page *page;
 		int may_enter_fs;
-		enum page_references references = PAGEREF_RECLAIM_CLEAN;
+		enum page_references references = PAGEREF_RECLAIM;
 		bool dirty, writeback;
 
 		cond_resched();
@@ -1248,7 +1248,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			}
 		}
 
-		if (!force_reclaim)
+		if (!skip_reference_check)
 			references = page_check_references(page, sc);
 
 		switch (references) {
-- 
2.21.0.1020.gf2820cf01a-goog