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 CF27AEEB57B for ; Thu, 1 Jan 2026 22:16:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4578A6B00AD; Thu, 1 Jan 2026 17:16:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4189C6B00AF; Thu, 1 Jan 2026 17:16:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 31AEF6B00B0; Thu, 1 Jan 2026 17:16:20 -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 207CB6B00AD for ; Thu, 1 Jan 2026 17:16:20 -0500 (EST) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id D7BDC5FA7F for ; Thu, 1 Jan 2026 22:16:19 +0000 (UTC) X-FDA: 84284804478.06.0DC0085 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf18.hostedemail.com (Postfix) with ESMTP id 5508A1C000F for ; Thu, 1 Jan 2026 22:16:18 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=tE9ASF2s; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf18.hostedemail.com: domain of frederic@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=frederic@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1767305778; a=rsa-sha256; cv=none; b=eE3BhpH9nkmxQUA7ttksPQWr7qeYX5x9xfReI+dXCXUtjdKRU1BqOdxD+mJpdvxMGoEyMt b5jt5OfDp/bSIKcLuEMgk0oRBppSnyzLm44GqtChSsvNvIMBmg+LQjIjrF0QUjassWdo7u OjnnBVQ2bv8FbE2Pj6OzxA/bty++9ws= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=tE9ASF2s; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf18.hostedemail.com: domain of frederic@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=frederic@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1767305778; 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=hWyf8gs1utEyG6vS35w8SHr2v2ULDUam3ZRD0EIO8gY=; b=asEn84NIGFqD3nILLeFW7+/d/se4p8gjtUS1cTClqP+5UGfNt1MvmJ6wVEPk6BwNcw127P +gBOspyTiVb1aQDwSU01ZDIr7Sy68+qgRA+g3rrO++RNoplK84gTM80t7soze7lDOLddlc MbIYJu9WyJ3GdOIsAF4JXd2+hnQIUns= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id D4A1760097; Thu, 1 Jan 2026 22:16:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D504C19422; Thu, 1 Jan 2026 22:16:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767305777; bh=dl/Gl7INrr4v6VbmH2ZxbRJCGrPgSwdt0Po/w4pDxAs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tE9ASF2sUjjhls9gA7k5g71gEtpYoRfUnZFPFHh3murIT3cAGCQrlbuYA3q7Vygaf pUXdGKf8D/FpxTsH9vIINsIYaDEwekDRq1+dbT9B5ZKgPWrXm39XIVnHCQS2HdlrL/ B5tY4zv34wQKj3uOvnIxCNveQ5SIy8Pdzzz4UhJnfraBdfBnK2xCfB90p7LrRbch0q p3AWNAk6UKrkLcFOT3mqiEdqmsdkyr9V/G/DP+c9e/ufCXoqliVrRjNS2Y+UCKdvYX Ri88SSuI/C7wsddEehR5NWB5Zx76VDYmaM9jiJ/Usx2GOwCihgjnvf7CZ9jXjbKFrS L7EjFh/Xthybw== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Andrew Morton , Bjorn Helgaas , Catalin Marinas , Chen Ridong , 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 15/33] sched/isolation: Flush memcg workqueues on cpuset isolated partition change Date: Thu, 1 Jan 2026 23:13:40 +0100 Message-ID: <20260101221359.22298-16-frederic@kernel.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20260101221359.22298-1-frederic@kernel.org> References: <20260101221359.22298-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 5508A1C000F X-Rspamd-Server: rspam10 X-Stat-Signature: 4xdz4ydgmz5ifejrtcqox1u8dexijqxc X-HE-Tag: 1767305778-436536 X-HE-Meta: U2FsdGVkX18iJMfgUpz/2BTAP1jjztfsPVr99JdL20L/G3Hh3yzI8MxW4+YtIP0Z7Bniz2LDeLoKlq7F97OEuAwAa/3DhzjofP12odp7XRiIeiMl75doaZ7KN1/BEstTsOWcbDdFqW1MHZfzI+j7QO/H3oLSeztb9DMx0BJdZ/rlkfwgU9DtZstHMbaV2zN0ALlRdJ0XIAD8aERXwLyYjox5f3p4aVFuwh7zcfCl7Ikc1TvxjwSmwyFdm9jxlSETNZKCWyKaXEvJD9DY7SnbGkxvzCq6iN5OshQEqN9bT3xJ8WdvJoN43IXpTX5FahKZOr1KRZI7UrVcUu2FtiB8HAGO/CLqYQzLzmYu1p42Svn5XmJKrA2j8fGjLszblQU5JYuOwkSnQYsGv/QRmapDreaPJtHl3H9fVXcEBVSOWV83jAqUzlZBK+SWxtX8K8xh1VPxDQmdmzwQYtIbiap0O8nPsXcSLc7VkzJ3p95LmdKeRhRt8lf/jgW8P0+zJswXyZYpQKE//v83m103G6BsE5n6vk902x6aab8YmWv+2WZMg7csJBmByE9/ltjDWFgQQvDIOCYgZl72mup29T81/S3Z++y0VPpVhy81dcx7HJEJf60oINzmlJzWTq4eFm8nDVwVuyk9mXyGHflGz3iVlEHVVDtJvCRI8OZfsgJ7uSEROaVefOgbIdb7gDtobHHV+qalYifJLJseCX8ARwtfEcuJzZ2uzLAAjjcRzHCi0LUVcGHHE9e8ak/W3p6L/3lWcJyRCmVtJT5DLaJ1Ew1VcOdmNP+zMB1Dipg+qvygtlD6XYLu7AakZCLKYqai5ClzaBSY459koZC+xnFy3dvDxd11BUF/4Yhapz1cjfzns4A5mlbObhFAY60FmYYzZkmqdIrLvkwZt5Xgq7i4QIQFwXRMZqkp1g1+sA1jFvIpvGNPRHhxC21IX1/JVQcb8lF1GjEsyORJJZc+H6afxFE plBDJqqS C3C6kwsOTtUqzOW1sp1UKM/OTbgRu5MY+cXeicGoRV5dDt0MvcrZcOFKu+fGVusSWCvbbPPBP7EN9lbSQzNEFz+V4pv9smrKg3yavwl6KVjg1my0uOGfNM46D238l+7Rokyy/MWmtqHsTI/zAATRpbbQCKXm9zju/0QlbdvZoaJdyvgMxljL84qUKyOqlkMw05IuxKZiJukg6FPaBI9JlTz4CsS6h68iBVLT4HOOyMTp76cRNcM56maSTekySD1GkHK/7Gly99oas6/VaBpMWvdzPX4nWcALWUqf1rEFX0DdYt8tevURF3NIIVQ== 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 is now modifiable at runtime. In order to synchronize against memcg workqueue to make sure that no asynchronous draining is still pending or executing on a newly made isolated CPU, the housekeeping susbsystem must flush the memcg workqueues. However the memcg workqueues can't be flushed easily since they are queued to the main per-CPU workqueue pool. Solve this with creating a memcg specific pool and provide and use the appropriate flushing API. Acked-by: Shakeel Butt Signed-off-by: Frederic Weisbecker --- include/linux/memcontrol.h | 4 ++++ kernel/sched/isolation.c | 2 ++ kernel/sched/sched.h | 1 + mm/memcontrol.c | 12 +++++++++++- 4 files changed, 18 insertions(+), 1 deletion(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 0651865a4564..5b004b95648b 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1037,6 +1037,8 @@ static inline u64 cgroup_id_from_mm(struct mm_struct *mm) return id; } +void mem_cgroup_flush_workqueue(void); + extern int mem_cgroup_init(void); #else /* CONFIG_MEMCG */ @@ -1436,6 +1438,8 @@ static inline u64 cgroup_id_from_mm(struct mm_struct *mm) return 0; } +static inline void mem_cgroup_flush_workqueue(void) { } + static inline int mem_cgroup_init(void) { return 0; } #endif /* CONFIG_MEMCG */ diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index c61b7ef3e98e..b5f9f974eac9 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -142,6 +142,8 @@ int housekeeping_update(struct cpumask *isol_mask) synchronize_rcu(); + mem_cgroup_flush_workqueue(); + kfree(old); return 0; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 653e898a996a..65dfa48e54b7 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -44,6 +44,7 @@ #include #include #include +#include #include #include #include diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2289a0299331..b3ca241bb1d6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -96,6 +96,8 @@ static bool cgroup_memory_nokmem __ro_after_init; /* BPF memory accounting disabled? */ static bool cgroup_memory_nobpf __ro_after_init; +static struct workqueue_struct *memcg_wq __ro_after_init; + static struct kmem_cache *memcg_cachep; static struct kmem_cache *memcg_pn_cachep; @@ -2013,7 +2015,7 @@ static void schedule_drain_work(int cpu, struct work_struct *work) */ guard(rcu)(); if (!cpu_is_isolated(cpu)) - schedule_work_on(cpu, work); + queue_work_on(cpu, memcg_wq, work); } /* @@ -5125,6 +5127,11 @@ void mem_cgroup_sk_uncharge(const struct sock *sk, unsigned int nr_pages) refill_stock(memcg, nr_pages); } +void mem_cgroup_flush_workqueue(void) +{ + flush_workqueue(memcg_wq); +} + static int __init cgroup_memory(char *s) { char *token; @@ -5167,6 +5174,9 @@ int __init mem_cgroup_init(void) cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, memcg_hotplug_cpu_dead); + memcg_wq = alloc_workqueue("memcg", WQ_PERCPU, 0); + WARN_ON(!memcg_wq); + for_each_possible_cpu(cpu) { INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, drain_local_memcg_stock); -- 2.51.1