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 878A943B6CD for ; Wed, 12 Aug 2026 12:18:48 +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=1786537129; cv=none; b=Zskg7RcdwN+W/Ah+tu8GCi+Nqp3ox5enc/VyvoSdNMbFF+h2nMh2JTUJVj5qbd3Nda7urjD/ZnEIzepXW5PrJiBQidU8cKq1jvdom6ToXCURuc4/N7MU/VPVhn0Po9Ihhi+WRe3xy6EKGjTsKgZUPD5SbTyH9tX0tuvrThYlXfo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786537129; c=relaxed/simple; bh=cL6TeHp3CJhfddBWBKj5iQj5eHcGqe1BtId8PCgl7o0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=U6Bdg6zAro7C8frtMWwFjSwD/T3Bt52k9ahhBxaJOcGbDJOTflCAQaF/T6QVXeAXcPWIzjaaWbNWo1wC66N3IDO3Su8x8eKcYbGj1O1QkUjd91e6UOOM4KDULH8BACq8r1XovwmvWl4r+8L6kcHVjpqZpTHNlktWH7GH0uOGpAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TDHRF0AA; 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="TDHRF0AA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B70D21F000E9; Wed, 12 Aug 2026 12:18:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786537128; bh=/7y18sjno+mqqfvWT6M0Hi+njMwHX33SQLnmAtAwqGs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TDHRF0AAx2OOlCm8oAlPxzA5y9oDBvujnLCSFyymC/pSzwTLhFqIjrF1qgCL+S6NC DHXGcfnZOjAWJKb84DOaCDsJa6v9Gu9OqqMyJ2+T3GCeV3qQEx9DDbXCIAEZgw50bn 17NeIAML5u6HK4eslYC7gpncgsV1041VbVBJYK7xUxCteC+Tbfd9AjKmrQZjrrAQfN B/cFvSsV8oAcNQy+IuR55UQXb+4kBk2WH29LN9D+8nTMRvCw9/liM8Hv+zItrxJCDK Vc1XiuvW3qT8RJBbT+SrqzX7T00HoUhIIhrjrvk8rwYlIuZ1yx3cGqqhE0O/J3zXCl Ao2pt8sE1CI7g== From: "Barry Song (Xiaomi)" To: akpm@linux-foundation.org, linux-mm@kvack.org Cc: axelrasmussen@google.com, 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, baolin.wang@linux.alibaba.com, baoquan.he@linux.dev, "Barry Song (Xiaomi)" Subject: [RFC PATCH v4 11/16] mm/mglru: skip gentle reclaim at DEF_PRIORITY for extreme swappiness Date: Wed, 12 Aug 2026 20:16:53 +0800 Message-Id: <20260812121658.69965-12-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260812121658.69965-1-baohua@kernel.org> References: <20260812121658.69965-1-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 For extreme swappiness (<= MIN_SWAPPINESS + 1 or >= MAX_SWAPPINESS), skip gentle reclaim. Falling back too easily, even at DEF_PRIORITY, undermines the effect of extreme swappiness. This matches the logic in get_type_to_scan(), where we have: if (swappiness <= MIN_SWAPPINESS + 1) return LRU_GEN_FILE; if (swappiness >= MAX_SWAPPINESS) return LRU_GEN_ANON; Signed-off-by: Barry Song (Xiaomi) --- mm/vmscan.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index b6c17ece3b3f..48a068b50678 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -281,6 +281,13 @@ static inline bool is_exec_file_folio(const struct folio *folio, return vma_flags_test(vma_flags, VMA_EXEC_BIT) && folio_is_file_lru(folio); } +/* See get_type_to_scan(): these values always select FILE or ANON */ +static inline bool is_extreme_swappiness(int swappiness) +{ + return swappiness <= MIN_SWAPPINESS + 1 || + swappiness >= MAX_SWAPPINESS; +} + static void set_task_reclaim_state(struct task_struct *task, struct reclaim_state *rs) { @@ -5094,8 +5101,11 @@ static bool should_run_aging(struct lruvec *lruvec, unsigned long max_seq, if (evictable_min_seq(min_seq, swappiness) + MIN_NR_GENS > max_seq) return true; - /* try to avoid aging, do gentle reclaim at the default priority */ - if (sc->priority == DEF_PRIORITY) + /* + * Try to avoid aging by doing gentle reclaim at the default + * priority. Skip gentle reclaim for extreme swappiness. + */ + if (sc->priority == DEF_PRIORITY && !is_extreme_swappiness(swappiness)) return false; /* better to run aging even though eviction is still possible */ -- 2.34.1