From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 78F8B204083 for ; Fri, 25 Jul 2025 02:14:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753409654; cv=none; b=MOWv4FbtH67aMgTvSSr36Pdiq0K2OnR3tdIAvrE1+likHShleAgXMbWtkvjSU4Bk0+19lxZzxqR09JnNYdrw2uD4Kq7OHRAoLeQzZUT5WVPGcDD2rAdmcqjmUW/uOMcrdnbV33hISVHqz+5Y9ENjdXX2Oon8bKHhfaoBQAe8nNE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753409654; c=relaxed/simple; bh=hCBQ2roIzznrueO4zdVqh4tRywmFjVUJyV71q68cHTo=; h=Date:To:From:Subject:Message-Id; b=IY59aAfSmYYaRlc54ehKzt2QrhLceY7KjOij4zURjo630dAWQ+s/b4QFAjR2Z4rqKrzI81eiI20QI4/iqAyNB8VvxzD0D/pUGBw3xgN5M2bnBzQ7sXnfyI3KwMnoVg1MLcX/OSfQ9zV8qh+GywlGsKQ2ovBUTIB2W7ZvegwTzEQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=T1+b898i; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="T1+b898i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEEBEC4CEED; Fri, 25 Jul 2025 02:14:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1753409654; bh=hCBQ2roIzznrueO4zdVqh4tRywmFjVUJyV71q68cHTo=; h=Date:To:From:Subject:From; b=T1+b898ipIYKZbZJYyv1TbCqvhzZWPkNADZsQSXhgd2b4vGOFNjdi8I5/NCE/cglc ixOKFdm46HTWXCK3xR/h9nsybmodvztji6Jnqd44YLnwcvMkXoAvSqIkKkUzyz/WQy 5z3NJK5ZYu5oGXs9IsIXumgnI1uhkNjvavtkY94A= Date: Thu, 24 Jul 2025 19:14:13 -0700 To: mm-commits@vger.kernel.org,zhengqi.arch@bytedance.com,yuzhao@google.com,yuanchu@google.com,shakeel.butt@linux.dev,mhocko@kernel.org,lorenzo.stoakes@oracle.com,kinseyho@google.com,hannes@cmpxchg.org,gthelen@google.com,david@redhat.com,axelrasmussen@google.com,jiahao1@lixiang.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-mglru-stop-try_to_inc_min_seq-if-min_seq-has-not-increased.patch removed from -mm tree Message-Id: <20250725021413.EEEBEC4CEED@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/mglru: stop try_to_inc_min_seq() if min_seq[type] has not increased has been removed from the -mm tree. Its filename was mm-mglru-stop-try_to_inc_min_seq-if-min_seq-has-not-increased.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Hao Jia Subject: mm/mglru: stop try_to_inc_min_seq() if min_seq[type] has not increased Date: Thu, 3 Jul 2025 10:39:46 +0800 In try_to_inc_min_seq(), if min_seq[type] has not increased. In other words, min_seq[type] == lrugen->min_seq[type]. Then we should return directly to avoid unnecessary overhead later. Corollary: If min_seq[type] of both anonymous and file is not increased, try_to_inc_min_seq() will fail. Proof: It is known that min_seq[type] has not increased, that is, min_seq[type] is equal to lrugen->min_seq[type], then the following: case 1: min_seq[type] has not been reassigned and changed before judgment min_seq[type] <= lrugen->min_seq[type]. Then the subsequent min_seq[type] <= lrugen->min_seq[type] judgment will always be true. case 2: min_seq[type] is reassigned to seq, before judgment min_seq[type] <= lrugen->min_seq[type]. Then at least the condition of min_seq[type] > seq must be met before min_seq[type] will be reassigned to seq. That is to say, before the reassignment, lrugen->min_seq[type] > seq is met, and then min_seq[type] = seq. Then the following min_seq[type](seq) <= lrugen->min_seq[type] judgment is always true. Therefore, in try_to_inc_min_seq(), If min_seq[type] of both anonymous and file is not increased, we can return false directly to avoid unnecessary overhead. Link: https://lkml.kernel.org/r/20250703023946.65315-1-jiahao.kernel@gmail.com Signed-off-by: Hao Jia Suggested-by: Yuanchu Xie Reviewed-by: Axel Rasmussen Cc: David Hildenbrand Cc: Greg Thelen Cc: Johannes Weiner Cc: Kinsey Ho Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Qi Zheng Cc: Shakeel Butt Cc: Yu Zhao Signed-off-by: Andrew Morton --- mm/vmscan.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/mm/vmscan.c~mm-mglru-stop-try_to_inc_min_seq-if-min_seq-has-not-increased +++ a/mm/vmscan.c @@ -3921,6 +3921,7 @@ static bool try_to_inc_min_seq(struct lr { int gen, type, zone; bool success = false; + bool seq_inc_flag = false; struct lru_gen_folio *lrugen = &lruvec->lrugen; DEFINE_MIN_SEQ(lruvec); @@ -3937,11 +3938,20 @@ static bool try_to_inc_min_seq(struct lr } min_seq[type]++; + seq_inc_flag = true; } next: ; } + /* + * If min_seq[type] of both anonymous and file is not increased, + * we can directly return false to avoid unnecessary checking + * overhead later. + */ + if (!seq_inc_flag) + return success; + /* see the comment on lru_gen_folio */ if (swappiness && swappiness <= MAX_SWAPPINESS) { unsigned long seq = lrugen->max_seq - MIN_NR_GENS; _ Patches currently in -mm which might be from jiahao1@lixiang.com are mm-mglru-update-mg-lru-proactive-reclaim-statistics-only-to-memcg.patch