linux-kernel - [RFC PATCH v3 4/6] workingset: simplify lru_gen_test

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Message-ID: <20230920190244.16839-5-ryncsn@gmail.com>
Date:   Thu, 21 Sep 2023 03:02:42 +0800
From:   Kairui Song <ryncsn@...il.com>
To:     linux-mm@...ck.org
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Yu Zhao <yuzhao@...gle.com>,
        Roman Gushchin <roman.gushchin@...ux.dev>,
        Johannes Weiner <hannes@...xchg.org>,
        Michal Hocko <mhocko@...e.com>,
        Hugh Dickins <hughd@...gle.com>, Nhat Pham <nphamcs@...il.com>,
        Yuanchu Xie <yuanchu@...gle.com>,
        Kalesh Singh <kaleshsingh@...gle.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        "T . J . Mercier" <tjmercier@...gle.com>,
        linux-kernel@...r.kernel.org, Kairui Song <kasong@...cent.com>
Subject: [RFC PATCH v3 4/6] workingset: simplify lru_gen_test_recent

From: Kairui Song <kasong@...cent.com>

Simplify the code, move some common path into its caller, prepare for
following commits.

Signed-off-by: Kairui Song <kasong@...cent.com>
---
 mm/workingset.c | 30 +++++++++++++-----------------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/mm/workingset.c b/mm/workingset.c
index 278c3b9eb549..87a16b6158e5 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -323,42 +323,38 @@ static void *lru_gen_eviction(struct folio *folio)
  * Tests if the shadow entry is for a folio that was recently evicted.
  * Fills in @lruvec, @token, @workingset with the values unpacked from shadow.
  */
-static bool lru_gen_test_recent(void *shadow, bool file, struct lruvec **lruvec,
-				unsigned long *token, bool *workingset)
+static bool lru_gen_test_recent(struct lruvec *lruvec, bool file,
+				unsigned long token)
 {
-	int memcg_id;
 	unsigned long min_seq;
-	struct mem_cgroup *memcg;
-	struct pglist_data *pgdat;
 
-	unpack_shadow(shadow, &memcg_id, &pgdat, token, workingset);
-
-	memcg = mem_cgroup_from_id(memcg_id);
-	*lruvec = mem_cgroup_lruvec(memcg, pgdat);
-
-	min_seq = READ_ONCE((*lruvec)->lrugen.min_seq[file]);
-	return (*token >> LRU_REFS_WIDTH) == (min_seq & (EVICTION_MASK >> LRU_REFS_WIDTH));
+	min_seq = READ_ONCE(lruvec->lrugen.min_seq[file]);
+	return (token >> LRU_REFS_WIDTH) == (min_seq & (EVICTION_MASK >> LRU_REFS_WIDTH));
 }
 
 static void lru_gen_refault(struct folio *folio, void *shadow)
 {
+	int memcgid;
 	bool recent;
-	int hist, tier, refs;
 	bool workingset;
 	unsigned long token;
+	int hist, tier, refs;
 	struct lruvec *lruvec;
+	struct pglist_data *pgdat;
 	struct lru_gen_folio *lrugen;
 	int type = folio_is_file_lru(folio);
 	int delta = folio_nr_pages(folio);
 
 	rcu_read_lock();
 
-	recent = lru_gen_test_recent(shadow, type, &lruvec, &token, &workingset);
+	unpack_shadow(shadow, &memcgid, &pgdat, &token, &workingset);
+	lruvec = mem_cgroup_lruvec(mem_cgroup_from_id(memcgid), pgdat);
 	if (lruvec != folio_lruvec(folio))
 		goto unlock;
 
 	mod_lruvec_state(lruvec, WORKINGSET_REFAULT_BASE + type, delta);
 
+	recent = lru_gen_test_recent(lruvec, type, token);
 	if (!recent)
 		goto unlock;
 
@@ -485,9 +481,6 @@ bool workingset_test_recent(void *shadow, bool file, bool *workingset)
 	struct pglist_data *pgdat;
 	unsigned long eviction;
 
-	if (lru_gen_enabled())
-		return lru_gen_test_recent(shadow, file, &eviction_lruvec, &eviction, workingset);
-
 	unpack_shadow(shadow, &memcgid, &pgdat, &eviction, workingset);
 
 	/*
@@ -511,6 +504,9 @@ bool workingset_test_recent(void *shadow, bool file, bool *workingset)
 		return false;
 	eviction_lruvec = mem_cgroup_lruvec(eviction_memcg, pgdat);
 
+	if (lru_gen_enabled())
+		return lru_gen_test_recent(eviction_lruvec, file, eviction);
+
 	return lru_test_refault(eviction_memcg, eviction_lruvec, eviction,
 				file, EVICTION_BITS, bucket_order);
 }
-- 
2.41.0