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 BC987D3B7E5 for ; Mon, 29 Dec 2025 03:24:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1BC166B0088; Sun, 28 Dec 2025 22:24:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 169F36B0089; Sun, 28 Dec 2025 22:24:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 075CF6B008A; Sun, 28 Dec 2025 22:24:08 -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 E77AF6B0088 for ; Sun, 28 Dec 2025 22:24:07 -0500 (EST) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 912151A1601 for ; Mon, 29 Dec 2025 03:24:07 +0000 (UTC) X-FDA: 84271064934.18.6638EB6 Received: from canpmsgout08.his.huawei.com (canpmsgout08.his.huawei.com [113.46.200.223]) by imf02.hostedemail.com (Postfix) with ESMTP id B76D28000D for ; Mon, 29 Dec 2025 03:24:04 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=huawei.com header.s=dkim header.b=S5oznL7E; spf=pass (imf02.hostedemail.com: domain of zhangqiao22@huawei.com designates 113.46.200.223 as permitted sender) smtp.mailfrom=zhangqiao22@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1766978645; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=+BDGPe6Wz623mn9DQDdS+J7GvS2xhqJ99bp8antJarY=; b=BOVoIu4NGYjzcZwKIZBJgVN6w8TdeXW14zvjaOU1dvJ2wTM5SZM+9xmGYafm5KoHJYWPvs KHV5Pw6yXI+xKeFps1NCYRFxoVh430BAPCSjk2UcWsJjMSdzK2HleUOpV0KhHP/4voOvjq bK2odhaWa6/nnQvB62Ks70m6LTyasFA= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=huawei.com header.s=dkim header.b=S5oznL7E; spf=pass (imf02.hostedemail.com: domain of zhangqiao22@huawei.com designates 113.46.200.223 as permitted sender) smtp.mailfrom=zhangqiao22@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1766978645; a=rsa-sha256; cv=none; b=kjzjbIcwZYeJ5nlyCZjdCIf+DpzYWX1m8UkLqSIBjA/g1OjLmwcOHl9lRGE6czTUw+v3LN 1bsRLGaIO+cpRNgUnUpTwbsMvg1Cm4xNsCN31RVN8r5gJSF22Bqj9Km4SxPDw5ev02AfYn 3xxI01Iiw25M5uMafXBVrcJm8S1pRsM= dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=+BDGPe6Wz623mn9DQDdS+J7GvS2xhqJ99bp8antJarY=; b=S5oznL7E1P+omaU+fUcM+wvPVZ/3cp/IsoQKCRwXkrHP4luHaqG+eOUxh9smTTkbEqw7uNvL0 c4F1Wz+fPO5F6LWQgHy3huRbvjOsFw6aJ5tzPzxeXifnT01IAPtQc9PeSF0XS6pqphA89L2jlAL eTXaNu0tOj/1OwY7Cqz7TxY= Received: from mail.maildlp.com (unknown [172.19.163.163]) by canpmsgout08.his.huawei.com (SkyGuard) with ESMTPS id 4dfhLm6PbPzmVYJ; Mon, 29 Dec 2025 11:20:48 +0800 (CST) Received: from dggpemf100017.china.huawei.com (unknown [7.185.36.74]) by mail.maildlp.com (Postfix) with ESMTPS id 5B2D440565; Mon, 29 Dec 2025 11:23:59 +0800 (CST) Received: from [10.67.111.186] (10.67.111.186) by dggpemf100017.china.huawei.com (7.185.36.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 29 Dec 2025 11:23:57 +0800 Message-ID: Date: Mon, 29 Dec 2025 11:23:56 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.1.1 Subject: Re: [PATCH 01/33] PCI: Prepare to protect against concurrent isolated cpuset change To: Frederic Weisbecker , LKML CC: =?UTF-8?Q?Michal_Koutn=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 , , , , , , References: <20251224134520.33231-1-frederic@kernel.org> <20251224134520.33231-2-frederic@kernel.org> From: Zhang Qiao In-Reply-To: <20251224134520.33231-2-frederic@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.111.186] X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To dggpemf100017.china.huawei.com (7.185.36.74) X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: B76D28000D X-Stat-Signature: 3cjtdwk1zu9g41s6bk7uii4wqcpz4eby X-HE-Tag: 1766978644-569646 X-HE-Meta: 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 hnSZEgKp jkvR9wTO6JQXTMr8VM4FFz0SWjlXk8aJMa5sIfBe9E84rPr9gVq/8oLOoPmrFH/O2QoWRDnx74geSTHFnteimLzlxTTGdO80pY9ouID7D+sbBz+ElecplqJcJ2n3vHI0w4u71SdaXuqy9LopDaw941WmVM6eb7N3vSyNx21Olg6RJXj9ddaSAE/tAzzercX9EXlcc6iPWT/m9qGmi2x68I6BJXEdCrEVGG+eRvkN6mvtBsD66x5/IPRa0qJOx/YrTYRx3vTlGgOXnzppNOtnbVO86+bX30mPRLX6Y0yTZhZotaPBzd1RAGvhtvhjm0nCsU0p8mLKf8GwvpQ0= 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: Hi, Weisbecker， 在 2025/12/24 21:44, Frederic Weisbecker 写道: > HK_TYPE_DOMAIN will soon integrate cpuset isolated partitions and > therefore be made modifiable at runtime. Synchronize against the cpumask > update using RCU. > > The RCU locked section includes both the housekeeping CPU target > election for the PCI probe work and the work enqueue. > > This way the housekeeping update side will simply need to flush the > pending related works after updating the housekeeping mask in order to > make sure that no PCI work ever executes on an isolated CPU. This part > will be handled in a subsequent patch. > > Signed-off-by: Frederic Weisbecker > --- > drivers/pci/pci-driver.c | 47 ++++++++++++++++++++++++++++++++-------- > 1 file changed, 38 insertions(+), 9 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index 7c2d9d596258..786d6ce40999 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -302,9 +302,8 @@ struct drv_dev_and_id { > const struct pci_device_id *id; > }; > > -static long local_pci_probe(void *_ddi) > +static int local_pci_probe(struct drv_dev_and_id *ddi) > { > - struct drv_dev_and_id *ddi = _ddi; > struct pci_dev *pci_dev = ddi->dev; > struct pci_driver *pci_drv = ddi->drv; > struct device *dev = &pci_dev->dev; > @@ -338,6 +337,19 @@ static long local_pci_probe(void *_ddi) > return 0; > } > > +struct pci_probe_arg { > + struct drv_dev_and_id *ddi; > + struct work_struct work; > + int ret; > +}; > + > +static void local_pci_probe_callback(struct work_struct *work) > +{ > + struct pci_probe_arg *arg = container_of(work, struct pci_probe_arg, work); > + > + arg->ret = local_pci_probe(arg->ddi); > +} > + > static bool pci_physfn_is_probed(struct pci_dev *dev) > { > #ifdef CONFIG_PCI_IOV > @@ -362,34 +374,51 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, > dev->is_probed = 1; > > cpu_hotplug_disable(); > - > /* > * Prevent nesting work_on_cpu() for the case where a Virtual Function > * device is probed from work_on_cpu() of the Physical device. > */ > if (node < 0 || node >= MAX_NUMNODES || !node_online(node) || > pci_physfn_is_probed(dev)) { > - cpu = nr_cpu_ids; > + error = local_pci_probe(&ddi); > } else { > cpumask_var_t wq_domain_mask; > + struct pci_probe_arg arg = { .ddi = &ddi }; > + > + INIT_WORK_ONSTACK(&arg.work, local_pci_probe_callback); > > if (!zalloc_cpumask_var(&wq_domain_mask, GFP_KERNEL)) { > error = -ENOMEM; If we return from here, arg.work will not be destroyed. > goto out; > } > + > + /* > + * The target election and the enqueue of the work must be within > + * the same RCU read side section so that when the workqueue pool > + * is flushed after a housekeeping cpumask update, further readers > + * are guaranteed to queue the probing work to the appropriate > + * targets. > + */ > + rcu_read_lock(); > cpumask_and(wq_domain_mask, > housekeeping_cpumask(HK_TYPE_WQ), > housekeeping_cpumask(HK_TYPE_DOMAIN)); > > cpu = cpumask_any_and(cpumask_of_node(node), > wq_domain_mask); > + if (cpu < nr_cpu_ids) { > + schedule_work_on(cpu, &arg.work); > + rcu_read_unlock(); > + flush_work(&arg.work); > + error = arg.ret; > + } else { > + rcu_read_unlock(); > + error = local_pci_probe(&ddi); > + } > + > free_cpumask_var(wq_domain_mask); > + destroy_work_on_stack(&arg.work); > } > - > - if (cpu < nr_cpu_ids) > - error = work_on_cpu(cpu, local_pci_probe, &ddi); > - else > - error = local_pci_probe(&ddi); > out: > dev->is_probed = 0; > cpu_hotplug_enable(); >