From mboxrd@z Thu Jan 1 00:00:00 1970 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 7F7A334CFB9; Wed, 24 Dec 2025 13:47:57 +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=1766584077; cv=none; b=kDhQLBZTz5vFTVZ9Fnt19BF2Vsc1UtleRBEZQ+8bR0BwvbfEHihHIHsOO5xslesDXiufsfiT90izF8H1NH5r2x4iW6l3jjoDtPgXNy2o/jtv5xTWRT71T+CtC2Cqr3f5J/H1mbMhIfAcXg4wTkxYU2Y+/5vZuqRFSb9FhAuKWws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766584077; c=relaxed/simple; bh=7qYWxx++pmNusXv4R4xraAF3RRpFsEpkHULEuTSFVcA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qCldc2PoZ7u4ZNhnUvhxkQwzSwafY759wbwvluFrB4C7860Zq8S/IRPoaZDH5P7VFDJmRUnAjyKYBzCQq/bWq9e3aT+rK4HRNuT7F0nX8qxUtCV2+Nb8rYnufPw9490XAPtoWlCi5hYednqbZo7Hz2u1YORkQ0LxZhkXgYn+vLU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mgxbtN3s; 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="mgxbtN3s" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74AEBC4CEFB; Wed, 24 Dec 2025 13:47:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766584077; bh=7qYWxx++pmNusXv4R4xraAF3RRpFsEpkHULEuTSFVcA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mgxbtN3soXaxGFkGtshSu3sETLrMlJFD82nO5TFfcJacIWGOhTQ+w/m2OIPUEg+UW 4vaHTNU/AHwz35/L1PwlH7RI0b8PfrOENgvkxhbQhmccOctFo2687Gxa50vDt3IYxs TSc1vvtuYQJDTSgciv+ciBzZN0J+Knv4pd4wzToU7bEH0waPbjiGwWOAa+c/P7+hSP 86lHadjQNahgmqghysF5Pun9Py8RA7sa3q+EyENqKTxmf/U6WsMedSDmeG1QX8mOuf sLC1gtYyWkDeMw0bZ/X9P/C//04luZOy4qKLKr16jz8Ub80z71p0n2XXxQlGnrzEzC faPNoWuE0m1HQ== 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 17/33] PCI: Flush PCI probe workqueue on cpuset isolated partition change Date: Wed, 24 Dec 2025 14:45:04 +0100 Message-ID: <20251224134520.33231-18-frederic@kernel.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251224134520.33231-1-frederic@kernel.org> References: <20251224134520.33231-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The HK_TYPE_DOMAIN housekeeping cpumask is now modifiable at runtime. In order to synchronize against PCI probe works and make sure that no asynchronous probing is still pending or executing on a newly isolated CPU, the housekeeping subsystem must flush the PCI probe works. However the PCI probe works can't be flushed easily since they are queued to the main per-CPU workqueue pool. Solve this with creating a PCI probe-specific pool and provide and use the appropriate flushing API. Signed-off-by: Frederic Weisbecker --- drivers/pci/pci-driver.c | 17 ++++++++++++++++- include/linux/pci.h | 3 +++ kernel/sched/isolation.c | 2 ++ 3 files changed, 21 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 786d6ce40999..d87f781e5ce9 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -337,6 +337,8 @@ static int local_pci_probe(struct drv_dev_and_id *ddi) return 0; } +static struct workqueue_struct *pci_probe_wq; + struct pci_probe_arg { struct drv_dev_and_id *ddi; struct work_struct work; @@ -407,7 +409,11 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, cpu = cpumask_any_and(cpumask_of_node(node), wq_domain_mask); if (cpu < nr_cpu_ids) { - schedule_work_on(cpu, &arg.work); + struct workqueue_struct *wq = pci_probe_wq; + + if (WARN_ON_ONCE(!wq)) + wq = system_percpu_wq; + queue_work_on(cpu, wq, &arg.work); rcu_read_unlock(); flush_work(&arg.work); error = arg.ret; @@ -425,6 +431,11 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, return error; } +void pci_probe_flush_workqueue(void) +{ + flush_workqueue(pci_probe_wq); +} + /** * __pci_device_probe - check if a driver wants to claim a specific PCI device * @drv: driver to call to check if it wants the PCI device @@ -1762,6 +1773,10 @@ static int __init pci_driver_init(void) { int ret; + pci_probe_wq = alloc_workqueue("sync_wq", WQ_PERCPU, 0); + if (!pci_probe_wq) + return -ENOMEM; + ret = bus_register(&pci_bus_type); if (ret) return ret; diff --git a/include/linux/pci.h b/include/linux/pci.h index 864775651c6f..f14f467e50de 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1206,6 +1206,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources); int pci_host_probe(struct pci_host_bridge *bridge); +void pci_probe_flush_workqueue(void); int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax); int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax); void pci_bus_release_busn_res(struct pci_bus *b); @@ -2079,6 +2080,8 @@ static inline int pci_has_flag(int flag) { return 0; } _PCI_NOP_ALL(read, *) _PCI_NOP_ALL(write,) +static inline void pci_probe_flush_workqueue(void) { } + static inline struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 8aac3c9f7c7f..7dbe037ea8df 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -8,6 +8,7 @@ * */ #include +#include #include "sched.h" enum hk_flags { @@ -145,6 +146,7 @@ int housekeeping_update(struct cpumask *isol_mask, enum hk_type type) synchronize_rcu(); + pci_probe_flush_workqueue(); mem_cgroup_flush_workqueue(); vmstat_flush_workqueue(); -- 2.51.1