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b=BhsHa0kkx6JhUcbZ5bXcyCYJwYlDmAZBdMVPOphK+IvpqwJKqNth/1zrxSvSXY7WS sXWiSoqqLIFc6B2dNm0DDSBMqsafiYoTq679FQJ0N8LzF9RzV+OAunClgn/F5+ryvi uqQy3iq6dJSedc7qBtrLVBxvYMcRVWjUrsIDWIvdXyw9wsygmMRMnPryHjR8rgc4U6 HNfnskuaKTqX1a1zhNJnSAubv5xlWJQ4EN4QZt/WbPhI1GIiZca6NbEL0u0lNAq3nx 3zpt1RGo6AnzavaQWZJe62Wv0/MOx35Pqz1VkxfgpZlynxhgoBxjO+WqHrRPPPott4 paYhCxu1upNuA== From: "Barry Song (Xiaomi)" To: akpm@linux-foundation.org, linux-mm@kvack.org Cc: axelrasmussen@google.com, baolin.wang@linux.alibaba.com, baoquan.he@linux.dev, chenridong@xiaomi.com, david@kernel.org, hannes@cmpxchg.org, kasong@tencent.com, lianux.mm@gmail.com, linux-kernel@vger.kernel.org, ljs@kernel.org, lyugaofei@xiaomi.com, mhocko@kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, stevensd@chromium.org, wangzicheng@honor.com, weixugc@google.com, yuanchu@google.com, zhangbo56@xiaomi.com, "Barry Song (Xiaomi)" Subject: [PATCH 6/6] mm/mglru: batch move folios to the second-oldest gen's LRU Date: Fri, 21 Aug 2026 18:25:38 +0800 Message-Id: <20260821102538.22642-7-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260821102538.22642-1-baohua@kernel.org> References: <20260821102538.22642-1-baohua@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Stat-Signature: g6ckbtq66cf15jks1c7noxbpm6n5y145 X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 441BF1C0004 X-HE-Tag: 1787308003-392410 X-HE-Meta: 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 h1nPegjw aYhlbglngA9pLgo5t3FNGD8G/7IkUV6X9MMc9xrpFH3wqcujhGeJyN1WQHHWun3ty1hJgw6gsRxSMTf8DBFJbBsmqcmnl4efYV+nBaXt/QW2/H/vRPXPBwU9i990wAJDYI1tXtW8NiEsFuMXqWPHbZHDXMoX0VPsZEYiQxAcRFTlnncEYt4/fw79oy6jgdMbXrmJY1t7zNMIWLJLuWq03OvxSAfGVBM02FiE5sh8DLEb8KSQS6SeeeA6sjyo1QSdsyF3/RV8F5fFd+L8KaYPxTB44oCkhV/sPddx3s173XDKJUm4kQxio0r+Azg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Detect folios that need to move from the oldest generation to the second-oldest generation, and batch-move them together. This can significantly reduce the sys time of inc_min_seq(), especially when the other type is significantly behind the preferred type. Assisted-by: gemini:gemini-3.6-flash Signed-off-by: Barry Song (Xiaomi) --- mm/vmscan.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 2fd82b2ca4d1..996b48344ed0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3923,6 +3923,19 @@ static void clear_mm_walk(void) kfree(walk); } +static inline void flush_lru_batch(struct list_head *head, struct list_head **batch_end, + struct list_head *dst) +{ + LIST_HEAD(movable); + + if (!*batch_end) + return; + + list_cut_position(&movable, head, *batch_end); + list_splice_tail_init(&movable, dst); + *batch_end = NULL; +} + static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness) { int zone; @@ -3942,9 +3955,11 @@ static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness) /* prevent cold/hot inversion if the type is evictable */ for (zone = 0; zone < MAX_NR_ZONES; zone++) { + struct list_head *target_list = &lrugen->folios[target_gen][type][zone]; struct list_head *head = &lrugen->folios[old_gen][type][zone]; unsigned long protected[MAX_NR_TIERS] = {}, delta = 0; struct list_head *pos = head->next; + struct list_head *batch_end = NULL; while (pos != head) { struct folio *folio = list_entry(pos, struct folio, lru); @@ -3963,7 +3978,8 @@ static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness) new_gen = __folio_inc_gen(folio, old_gen, &gen_increased); if (gen_increased) { delta += nr_pages; - list_move_tail(&folio->lru, &lrugen->folios[new_gen][type][zone]); + batch_end = &folio->lru; + /* don't count the workingset being lazily promoted */ if (refs + workingset != BIT(LRU_REFS_WIDTH) + 1) { int tier = lru_tier_from_refs(refs, workingset); @@ -3971,11 +3987,14 @@ static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness) protected[tier] += nr_pages; } } else { + flush_lru_batch(head, &batch_end, target_list); list_move(&folio->lru, &lrugen->folios[new_gen][type][zone]); } if (!--remaining) break; } + flush_lru_batch(head, &batch_end, target_list); + WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone], lrugen->nr_pages[old_gen][type][zone] - delta); WRITE_ONCE(lrugen->nr_pages[target_gen][type][zone], -- 2.34.1