From nobody Mon Apr 6 10:30:44 2026 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 B9A9D30B537; Mon, 13 Oct 2025 20:33:49 +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=1760387629; cv=none; b=tsWmvoNFB2RITFRyuwn5wysfJ9sUWvtkKE+YdSNOJte6heNydjqrVAr4n3GK3rfqLFAkHBdeW6SjDwJ3+Ce5fplcsJXht/GTAGOK5LVd+ADeUTr5Vk/nm7HInhHuG+hdES/l5WdDcZTjh3mXcyGW1dmslXOd4VTxJpE7gz7X/Ks= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760387629; c=relaxed/simple; bh=9oNpqgYjTcFMTbPZgxvfSlFc0ojQ77K/A/hD7MumAUQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=s8tVpExRnLhIzJSFW8RXHpwn7wMLNccEs5r448r+4Ttv5vSUXTfpyWxy9zx6Rt8kM10TTv0Fs9RPyuEno9qrebHlVaEVzaIRmB13bYc+OytHyD3+0mm7yhsT/O680M6b5U5jg0uonMgwy7bHx/98GhABU6f3bbQ3JLEw2mHsapM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lcJiOQax; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lcJiOQax" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D11E6C116C6; Mon, 13 Oct 2025 20:33:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760387629; bh=9oNpqgYjTcFMTbPZgxvfSlFc0ojQ77K/A/hD7MumAUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lcJiOQaxzRbm/vnW/7YplQp1SHR/EYlMBi81fjw8+ud9d0xJzG/M5ydBd35kgDQby MGqZa1++jHkG6de3/IShSXu/VPNz255mdDROulIq+v6Msd8lxXjl5Zb0UU1z8IA47e u6UfgSZdJL9zfVNfvzwCazayfzsHaagNZ8IfWgHaJNYwwnscuTLrgjDyCNihTr+akx w+H3pKN0hhDNQa+5kpthY11CkItIJJx8FHnkJgmoyYikqWxZnes+oPl9WfT239ZviD 2FAqBS3l3+R+gy+jLzqrv5oDUAFlF0mcRVnV6DrqPx+70lF5/NxORiMhMXicUM8yH1 LMYrBX6aQoFiw== 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 14/33] sched/isolation: Flush memcg workqueues on cpuset isolated partition change Date: Mon, 13 Oct 2025 22:31:27 +0200 Message-ID: <20251013203146.10162-15-frederic@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013203146.10162-1-frederic@kernel.org> References: <20251013203146.10162-1-frederic@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: quoted-printable Content-Type: text/plain; charset="utf-8" The HK_TYPE_DOMAIN housekeeping cpumask is now modifyable 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 873e510d6f8d..001200df63cf 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1074,6 +1074,8 @@ static inline u64 cgroup_id_from_mm(struct mm_struct = *mm) return id; } =20 +void mem_cgroup_flush_workqueue(void); + extern int mem_cgroup_init(void); #else /* CONFIG_MEMCG */ =20 @@ -1481,6 +1483,8 @@ static inline u64 cgroup_id_from_mm(struct mm_struct = *mm) return 0; } =20 +static inline void mem_cgroup_flush_workqueue(void) { } + static inline int mem_cgroup_init(void) { return 0; } #endif /* CONFIG_MEMCG */ =20 diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 95d69c2102f6..9ec365dea921 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -144,6 +144,8 @@ int housekeeping_update(struct cpumask *mask, enum hk_t= ype type) =20 synchronize_rcu(); =20 + mem_cgroup_flush_workqueue(); + kfree(old); =20 return 0; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 8fac8aa451c6..8bfc0b4b133f 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 1033e52ab6cf..1aa14e543f35 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -95,6 +95,8 @@ static bool cgroup_memory_nokmem __ro_after_init; /* BPF memory accounting disabled? */ static bool cgroup_memory_nobpf __ro_after_init; =20 +static struct workqueue_struct *memcg_wq __ro_after_init; + static struct kmem_cache *memcg_cachep; static struct kmem_cache *memcg_pn_cachep; =20 @@ -1975,7 +1977,7 @@ 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); } =20 /* @@ -5092,6 +5094,11 @@ void mem_cgroup_sk_uncharge(const struct sock *sk, u= nsigned int nr_pages) refill_stock(memcg, nr_pages); } =20 +void mem_cgroup_flush_workqueue(void) +{ + flush_workqueue(memcg_wq); +} + static int __init cgroup_memory(char *s) { char *token; @@ -5134,6 +5141,9 @@ int __init mem_cgroup_init(void) cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, memcg_hotplug_cpu_dead); =20 + memcg_wq =3D alloc_workqueue("memcg", 0, 0); + WARN_ON(!memcg_wq); + for_each_possible_cpu(cpu) { INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, drain_local_memcg_stock); --=20 2.51.0