From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93A3D37F006 for ; Thu, 27 Aug 2026 23:47:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787874462; cv=none; b=uljW3WQePXBVhNH+JzCdUtDH056nAianNHja94HxjGad+53MgUFMMoXit4Ce5muTqvzrNywrlIkhP+ne8d8329zNnqNE7hhDWouKv78b+vRQL4kLfmiBIVVgZy+h2cRe5Vs+62luw4/KUgfuzTKDyu6uFTcUUcUyvw9E9ga9eu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787874462; c=relaxed/simple; bh=Hxje9xumeitE6b5gN/GluFPkClYPXrs+5wmzMTCtK84=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=W97/s//niU+YIi9rzGBldOSWwzb4VAPz+d4L3VI0Qu5NX6jAxsr2761NdqgSqsG6C9/XcONssc9blYUDTe2wCJTqgij0VT38BU7PlKHObM+T2ysjvw6sdd1OTmUo78LCg7v16QXzDsnTU9JlGRJfgAnHYDqKob9Nb72ClDzp5Gk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vjf35Uvk; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vjf35Uvk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFAA61F00A3D; Thu, 27 Aug 2026 23:47:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787874461; bh=qItSZf2IMrcadC3doUN+qm71ZNZWkB8tfnyRrPNJHJY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Vjf35UvktgdHiWQIABTxMqaWim3kr4E58NO+7gveoHzr9gSUuODU+e/oPsz6xDDHU d6molKBbiRPKf84hwQk5MKnfAuzKDUvOceSBI8UxSANtm2F+olNrsbn5M7PiwmhDF4 1kKleza67ZT3+22y7hBv665q2bHi7AxrnTMwcJ4denIPhChL6ThTf0gCjWYRftQ07V 6neNqlatpZ5vqdsoIPzu+ElSTTYbCqaIJy0yQceQLtwjMRP4rUSfNMSOMd6BiyFW1r fWy8QvSUkhZ5kR2k0z0bhGFCEUppN14Hvwa8EoskbbyiCtYlmsixo0qaEdRzsuzG2M f8+Xe0GMMdlrA== From: "Barry Song (Xiaomi)" To: akpm@linux-foundation.org, lianux.mm@gmail.com 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, linux-kernel@vger.kernel.org, linux-mm@kvack.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)" , Xueyuan Chen Subject: [PATCH v2 7/7] mm/mglru: batch move folios to the second-oldest gen's LRU Date: Fri, 28 Aug 2026 07:47:04 +0800 Message-Id: <20260827234704.63163-8-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260827234704.63163-1-baohua@kernel.org> References: <20260827234704.63163-1-baohua@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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) Reviewed-by: Baoquan He Tested-by: Xueyuan Chen --- mm/vmscan.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 17524e96fe64..2b6f3f05ce60 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3931,6 +3931,19 @@ 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; @@ -3953,8 +3966,10 @@ static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness) lru_gen_is_active(lruvec, target_gen)); /* 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]; struct list_head *pos = head->next; + struct list_head *batch_end = NULL; long delta = 0; while (pos != head) { @@ -3974,7 +3989,7 @@ 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) { @@ -3984,11 +3999,14 @@ static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness) lrugen->protected[hist][type][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