From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5743E106ACED for ; Thu, 12 Mar 2026 20:53:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B626D6B00A6; Thu, 12 Mar 2026 16:53:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B37FE6B00A7; Thu, 12 Mar 2026 16:53:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9F9EF6B00A8; Thu, 12 Mar 2026 16:53:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8CA996B00A6 for ; Thu, 12 Mar 2026 16:53:34 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 45CE61B7E48 for ; Thu, 12 Mar 2026 20:53:34 +0000 (UTC) X-FDA: 84538611948.27.C1431AC Received: from mail-qv1-f45.google.com (mail-qv1-f45.google.com [209.85.219.45]) by imf12.hostedemail.com (Postfix) with ESMTP id 6F3FF4000B for ; Thu, 12 Mar 2026 20:53:32 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=cmpxchg.org header.s=google header.b=bo90t1Eo; spf=pass (imf12.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.219.45 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org; dmarc=pass (policy=none) header.from=cmpxchg.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1773348812; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Aqbg0K2IsgJ/qrqREwPFlBusaMsCq6IazOmM3TBzhTA=; b=G9mJWAFUQLWykKqGRHeA53vOOZZs/s/YsuMSYGrd6yM8i+1S4VAv5ZlKKAjxXs1fpNZF+i v78wu6KgH3vjONqYuYsXpLEA1Y5UtzrqnDtsB7xHVFQCxb+AWxXbGnjVboOgLBh93+1EUz VcUyaPOr/6JFhwDdOxamGiuvU5XRvEM= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=cmpxchg.org header.s=google header.b=bo90t1Eo; spf=pass (imf12.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.219.45 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org; dmarc=pass (policy=none) header.from=cmpxchg.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1773348812; a=rsa-sha256; cv=none; b=XfxY8wr/kF44Ip//EMWX7cCZ9V/sviRYWZN6rdzHCZNGavqeknaS9xfvWgi9SOoSJgvaME cx0f5wbP/Ri6ZfBrSzyy2MWwuzpFqoHPFRZhGjmUWyVORLYMjjLgUeKZBFMeJKBcpTrcnw M+FkfpF3YQ0lAFunEsHGYSBjR4qcB/E= Received: by mail-qv1-f45.google.com with SMTP id 6a1803df08f44-89a465bd7edso11375366d6.0 for ; Thu, 12 Mar 2026 13:53:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg.org; s=google; t=1773348811; x=1773953611; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Aqbg0K2IsgJ/qrqREwPFlBusaMsCq6IazOmM3TBzhTA=; b=bo90t1EoljYFUtC49qy03Aq6wt2qHzsccBA8K2IfmdbBkDqzjsJN03S8c9tC63K50i mffrSxYttKtHohJ74D23fbyLB6sAfl+JLycvFs8R7gWAHRbs4Ev7hHTsrAre5hbXf3PE Te0EeXdJFaUBORila3opH8lLMvl+uag5K6yapKKNoklGhbQUDG33KUyZsFGTziu4cuhz 6Rpmvx0C4CZo20jz3CFEGrc3owyWVg+FiIgxHVEbW5Gas6sGo7RQL9EjryYILx9piZtx 66m2bGp2Z3hj2AwceD3yzzFiyqxq9/5rvjc784hFTq3nf4XT4ZN6RVGj9IQKxTXUBdJY QxVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1773348811; x=1773953611; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=Aqbg0K2IsgJ/qrqREwPFlBusaMsCq6IazOmM3TBzhTA=; b=MHbuh9kHD4lUbuVhYOTS+Z4BnM9Y/LNbGTsDuc2aosnuRbUZtDIUPWe46UAR76u0cg 3GauPZhp3bqhAoxu+U1o3nnMxqxTb7ibInTeoFbovgO8PzerL7j/3jz4xUGVyXzAjctQ cMuEhL5FOpRW0v4bKJ6+Xx8MFISP+fD8nOqAocWtNs5/vak+IdymxwVDuF0P3axuUJul ybjpRgolKKrZ0fhGzh7Ju7pdigRX7Gu3yH/ZBdXcrPJDaz+aZyzP4Hx7q17e9Qm5Su7S ghVLT1q0WqBb6IiWssbBuRK7FNJ1Cb+iwToIsGRia9K4NmPxDyBXJhk5AMH9s4BNo0GX Ckaw== X-Forwarded-Encrypted: i=1; AJvYcCVTGwidKjKjZ38k6wS1LNxP7eTcPFVkAuinfRnO+gSnVEKTVSC6+tDSjKwXUP6uWwvLaDh59zux8w==@kvack.org X-Gm-Message-State: AOJu0YwikPDCTDIQAz+zsGml8NLdSK57pupRXTvP8mywPsX6U6rfyGn6 ykcrrtigLes0KbLiRaAOjgOi2StJqkXPCKBUSgynwukrzifA600GQECFglujh7Z1wEE= X-Gm-Gg: ATEYQzyWbCEDLeDZ92erESPHiegdJqjgO19GzivvbD0Kqcgg9m4fdeBW+tzG1ZoG1uq 8YkzIUhgiSkldjgE4CRw0UbtYJLlR72kgtcy/nqpHw1NrENJXBkxv6YaK0RTowDm8fJ3nTgsxod jnwQm9OxJHPMI4vkF9TT5Aoor8xKI7Z7mOD+NQXKofGAcK578rQcU2P0KoGPzVWjqMKWEmDgbIm qAmzBxmOYrQcgUgSYM8+FY11z4ZUibr8N8D+JdXDItudyweJIjTba17+L4ZVT5RRYlNqynsyrNk pAGvkM0Qj0SB1BbqJHZC68IN5fcVtetBq5NQ6UfsJBDtc5jAokgfLkHsnISJgafnYFi73RJD3fF NDphRon1Lshi4gymNCdDJRh+3FiaO5eOCBaWn9RPP1IfdbTvJhVJcWjszxdCOaKx8uVqQ0StDFc X5Zmblj5mvuOr+jDZxU2C9Xg== X-Received: by 2002:a05:6214:1c41:b0:896:fa50:4c0c with SMTP id 6a1803df08f44-89a81f5282emr14261866d6.53.1773348811497; Thu, 12 Mar 2026 13:53:31 -0700 (PDT) Received: from localhost ([2603:7000:c00:3a00:365a:60ff:fe62:ff29]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-89a65c0d327sm42509556d6.22.2026.03.12.13.53.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Mar 2026 13:53:30 -0700 (PDT) From: Johannes Weiner To: Andrew Morton Cc: David Hildenbrand , Shakeel Butt , Yosry Ahmed , Zi Yan , "Liam R. Howlett" , Usama Arif , Kiryl Shutsemau , Dave Chinner , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/7] mm: list_lru: lock_list_lru_of_memcg() cannot return NULL if !skip_empty Date: Thu, 12 Mar 2026 16:51:49 -0400 Message-ID: <20260312205321.638053-2-hannes@cmpxchg.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260312205321.638053-1-hannes@cmpxchg.org> References: <20260312205321.638053-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 6F3FF4000B X-Rspamd-Server: rspam08 X-Stat-Signature: 4mizp5cx8d9p1by7wa3cjrq8cq56um8j X-HE-Tag: 1773348812-240300 X-HE-Meta: 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 cowTwIv+ Uq7M4Hc0MK/tlG+OsSISd1F01T7RT542l9H5Q+2PJ+rPcj6Xa+xmqyouMyD7+yXlkMymzZ47pEmhUHCeyZDUv4ukLdlUeaTak/CVLs0h4y7wfQ5JSzqvjVZ9sH6vWMBS7WEEXzLE+/T20GN3ahwNeWD+8fXs3TsDB0c7xs6mc6DITdLUT50CAweM3gqMDJIxNmmcU3zHq57feN5AaofI8AX3VRYdi4RGvzXtf9MhGUAsDnqCIY7K8pVnL/HOTXWsr/nV020QJmnairW2x+Lehf4lVorIXyzkjXnzFxhPyIOpOBaZJzBApdBmyfKk8pJmfDXgCkjtKtsnV+1tQW7lyzNKIs7BS/Mh9COLpj0oMFVrZthHQx7E/Wp/lm8IF9om20MmLL4mNDVSbtDSe0eRWs8dl9tX6EcuhWiGVyvCCI2DendF/aTYRPbG+y/cuvG5GfFMte4BVI9kpARawdYrruHpf2FDMlmjCH8Gt Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: skip_empty is only for the shrinker to abort and skip a list that's empty or whose cgroup is being deleted. For list additions and deletions, the cgroup hierarchy is walked upwards until a valid list_lru head is found, or it will fall back to the node list. Acquiring the lock won't fail. Remove the NULL checks in those callers. Signed-off-by: Johannes Weiner --- mm/list_lru.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/mm/list_lru.c b/mm/list_lru.c index 26463ae29c64..d96fd50fc9af 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -165,8 +165,6 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item, int nid, struct list_lru_one *l; l = lock_list_lru_of_memcg(lru, nid, memcg, false, false); - if (!l) - return false; if (list_empty(item)) { list_add_tail(item, &l->list); /* Set shrinker bit if the first element was added */ @@ -203,9 +201,8 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item, int nid, { struct list_lru_node *nlru = &lru->node[nid]; struct list_lru_one *l; + l = lock_list_lru_of_memcg(lru, nid, memcg, false, false); - if (!l) - return false; if (!list_empty(item)) { list_del_init(item); l->nr_items--; -- 2.53.0