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b=j2p2p/pmAqoVZ9r4zJMNX8O3DdOIzV9h7PhopbCDJwq1qoaD4iCS+CfXSKD3vtVTj JceEjLIXTrqQwfGz7D6OV2HQLza5sBt/admhX8WvGgvwRKU5sfwq0TXG/vAr/IDt4W WOwwwb6vKeOL2lM3wnKJOsJg3NKKVA9a8g1n1nhlrcufg/HWcggaQYwJBbVOPimOXT YmwqVVcfqhYAYqFEFRHuQboNPPy+//tTTii//TlKPYnsD6aUlQ6wRqF0b/CmIa2Xc/ NlyVIsNLZK/5GrFzcaKzJpGLhPnd88AjqbVdrW81DqoaV+NlP9juzpINfC0V2z2U/Z c7y/W0QErFFQA== From: "Barry Song (Xiaomi)" To: akpm@linux-foundation.org, linux-mm@kvack.org Cc: hui.zhu@linux.dev, axelrasmussen@google.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, david@kernel.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, ljs@kernel.org, mhocko@kernel.org, qi.zheng@linux.dev, ryncsn@gmail.com, shakeel.butt@linux.dev, weixugc@google.com, yuanchu@google.com, zhuhui@kylinos.cn, baoquan.he@linux.dev, liuxiang.277@bytedance.com, wangzicheng@honor.com, lianux.mm@gmail.com, kasong@tencent.com, liam@infradead.org, surenb@google.com, mhocko@suse.com, rppt@kernel.org, zhangbo56@xiaomi.com, lyugaofei@xiaomi.com, ridong.chen@linux.dev, kunwu.chan@gmail.com Subject: [RFC PATCH v5 11/14] mm/mglru: Reduce LRU lock contention by shrinking folio batches in inc_min_seq Date: Fri, 23 Oct 2026 06:02:00 +0800 Message-Id: <20261022220203.91911-12-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20261022220203.91911-1-baohua@kernel.org> References: <20261022220203.91911-1-baohua@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 3E89B1C000C X-Stat-Signature: ha7n87o7dwdn8u3tcq9f8cdopw4j8e35 X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1792706591-392308 X-HE-Meta: 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 JvtVOcMp Wk01RxsGK0awpfujpXWiG3L4NN8aMB5xWsWvJeZoEHfRKQivm6uht/XKF6EyFelI22WE4ULF84EO7yEtAS2A/pOFs45AckNVMbYHiXKGG9bK64NWZ4Nv8P36ybaZd/pZidr2IhOfLWluh8gpCNq4qNrBH9dhJC6eFmx4OfGkYCKe2yKp5/Nz8TilZW3h8gXi1dU7Xhiwu1G1LFPGM3kc1tIswiB7cMIvQKFJPZgLuUiyHKBgbWanRs1lumsE1cjf8mNo5AVpkUi9JiMqHEzVtUaD3aEYy4AABCaERGxQMSBlrdvhf011keKsnk/grJfuAXkXH2d23TGHxyv9BScoU1xyVzhDKDNzOJHN+ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Reduce the number of folios moved from the oldest generation to the second-oldest generation in each batch. This shortens the time the lruvec lock is held, allowing concurrent LRU operations to make progress and significantly reducing LRU lock contention. Signed-off-by: Barry Song (Xiaomi) --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index e8eeeeb76282..555359cc0368 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4051,7 +4051,7 @@ static inline void flush_lru_batch(struct list_head *head, struct list_head **ba static bool inc_min_seq(struct lruvec *lruvec, int type, int swappiness) { int zone; - int remaining = MAX_LRU_BATCH; + int remaining = MIN_LRU_BATCH; struct lru_gen_folio *lrugen = &lruvec->lrugen; int hist = lru_hist_from_seq(lrugen->min_seq[type]); int new_gen, old_gen = lru_gen_from_seq(lrugen->min_seq[type]); -- 2.34.1