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 93A40CCFA13 for ; Wed, 5 Nov 2025 21:04:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E20108E0010; Wed, 5 Nov 2025 16:04:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id DF7C68E0002; Wed, 5 Nov 2025 16:04:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CE73C8E0010; Wed, 5 Nov 2025 16:04:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id B7E0C8E0002 for ; Wed, 5 Nov 2025 16:04:28 -0500 (EST) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 55CBBB9AFD for ; Wed, 5 Nov 2025 21:04:28 +0000 (UTC) X-FDA: 84077781816.25.9DD374B Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf21.hostedemail.com (Postfix) with ESMTP id A427F1C0012 for ; Wed, 5 Nov 2025 21:04:26 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=LTjEW+Lp; spf=pass (imf21.hostedemail.com: domain of frederic@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=frederic@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762376666; 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=7jsS0D1ZkHtkf2RkO8oWUbGdG/MMM9S/GrtgH5Fheqs=; b=3+wFA9hidPuv3o8H1nobsJh28hf1yg0ORyJWa9MXlekhS5JPjr2v/OHctEO7yy5qcYdw4f NpciRgNRFvh3TV1RWYCRwrHNfFD0/DuPMOTtR1XNi7vDeLjyeg7eHRSKKR8YVZTc5RTDjB LX3AQjPFxEdbas6Y4rBfU5a8kE7EjL0= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=LTjEW+Lp; spf=pass (imf21.hostedemail.com: domain of frederic@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=frederic@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762376666; a=rsa-sha256; cv=none; b=seAV7Yi1shrwcpAgKuXV3ILqozEerQx5VCbsR+1pNHZuiNvNFDi7lAGG6SjdAcGklXeHve ZyPXQhBFU2PYVABS+pqVcDZJbjRb/sY8APl6OFsSiCnb2u6g+yneR5zfSR9h+fsCoZ7+Hg TgQh6358qgulnVpsh5exTj0GYGc2rJE= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id BB333417B1; Wed, 5 Nov 2025 21:04:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C864C116B1; Wed, 5 Nov 2025 21:04:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762376665; bh=QDY6OFwPCpaj5eQjhmw6Wwop/7HtBl8sFRDTAL/mseY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LTjEW+LpKe78Iwb5IpUCFicQk91WKrouEhNOVkCIWNJWT/IUfA+/1BuMRMTE/GSNf +H7F8egVjXkx/lSP96kC+SuuJLTGF/8XU6ILZHU9JyBzgy3HxvUFPliaEIO6h0Pw4Q NVPHhj8BuptnLIKmapcvKpE/aGeO4jSutNhuT0C4PABWjnpD9Q5cuNIdyWXg3giORC Fi9PFedNEfYKwdFXqkXdRc0iWC1GJiQi2RRoWyt+ov+H9uiPm/BOjklQPfkM6OtIbG I2NCBOxhuNhTQcrNQ8aEH7WXQtqQYaJPe3rmjJTxzn9fdSN39b2M5jDqPW6Yafqx0c MhWXAmuKuHXaw== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Andrew Morton , Bjorn Helgaas , Catalin Marinas , Danilo Krummrich , "David S . Miller" , Eric Dumazet , Gabriele Monaco , Greg Kroah-Hartman , Ingo Molnar , Jakub Kicinski , Jens Axboe , Johannes Weiner , Lai Jiangshan , Marco Crivellari , Michal Hocko , Muchun Song , Paolo Abeni , Peter Zijlstra , Phil Auld , "Rafael J . Wysocki" , Roman Gushchin , Shakeel Butt , Simon Horman , Tejun Heo , Thomas Gleixner , Vlastimil Babka , Waiman Long , Will Deacon , cgroups@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 03/31] memcg: Prepare to protect against concurrent isolated cpuset change Date: Wed, 5 Nov 2025 22:03:19 +0100 Message-ID: <20251105210348.35256-4-frederic@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251105210348.35256-1-frederic@kernel.org> References: <20251105210348.35256-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: A427F1C0012 X-Stat-Signature: m4yrfaaqnhpu61jin655uckomu87c84s X-Rspam-User: X-HE-Tag: 1762376666-4927 X-HE-Meta: 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 AzRgfsY6 MSzAQoIwpWX/2ryzST0iqBGMEY3R4QmQnk947kdZTzDbKfT9dJxLA6UR/sOCzmzN3q5ibHrZIubsUZ3Leqtt8PqPdA94iRjuzycrw7b7BLKyVlceTXxldYCvLqGhIqhlAGaDygs9Cr3GIYUAeJv+2Ye6PlNHDEwuavspaVAI0cr8FkBj/xUoqWq/1z7yAjm/NyNzlE7geu44wDaKTXwWG7WsVLtSCy0LM50atS8vZc2zq9sDLQD8bjZXM9wQKP7jioIlwPQF0PzqSB+k= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: The HK_TYPE_DOMAIN housekeeping cpumask will soon be made modifiable at runtime. In order to synchronize against memcg workqueue to make sure that no asynchronous draining is pending or executing on a newly made isolated CPU, target and queue a drain work under the same RCU critical section. Whenever housekeeping will update the HK_TYPE_DOMAIN cpumask, a memcg workqueue flush will also be issued in a further change to make sure that no work remains pending after a CPU has been made isolated. Signed-off-by: Frederic Weisbecker --- mm/memcontrol.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4deda33625f4..1033e52ab6cf 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1971,6 +1971,13 @@ static bool is_memcg_drain_needed(struct memcg_stock_pcp *stock, return flush; } +static void schedule_drain_work(int cpu, struct work_struct *work) +{ + guard(rcu)(); + if (!cpu_is_isolated(cpu)) + schedule_work_on(cpu, work); +} + /* * Drains all per-CPU charge caches for given root_memcg resp. subtree * of the hierarchy under it. @@ -2000,8 +2007,8 @@ void drain_all_stock(struct mem_cgroup *root_memcg) &memcg_st->flags)) { if (cpu == curcpu) drain_local_memcg_stock(&memcg_st->work); - else if (!cpu_is_isolated(cpu)) - schedule_work_on(cpu, &memcg_st->work); + else + schedule_drain_work(cpu, &memcg_st->work); } if (!test_bit(FLUSHING_CACHED_CHARGE, &obj_st->flags) && @@ -2010,8 +2017,8 @@ void drain_all_stock(struct mem_cgroup *root_memcg) &obj_st->flags)) { if (cpu == curcpu) drain_local_obj_stock(&obj_st->work); - else if (!cpu_is_isolated(cpu)) - schedule_work_on(cpu, &obj_st->work); + else + schedule_drain_work(cpu, &obj_st->work); } } migrate_enable(); -- 2.51.0