On Thu, Jan 01, 2026 at 11:13:48PM +0100, Frederic Weisbecker wrote:
> It doesn't make sense to use nohz_full without also isolating the
> related CPUs from the domain topology, either through the use of
> isolcpus= or cpuset isolated partitions.
>
> And now HK_TYPE_DOMAIN includes all kinds of domain isolated CPUs.
>
> This means that HK_TYPE_KERNEL_NOISE (of which HK_TYPE_WQ is only an
> alias) should always be a subset of HK_TYPE_DOMAIN.
>
> Therefore sane configurations verify:
>
> HK_TYPE_KERNEL_NOISE | HK_TYPE_DOMAIN == HK_TYPE_DOMAIN
>
> Simplify the PCI probe target election accordingly.
>
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
> drivers/pci/pci-driver.c | 17 +++--------------
> 1 file changed, 3 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index b902d8adf9a5..a9590601835a 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -384,16 +384,9 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
> pci_physfn_is_probed(dev)) {
> error = local_pci_probe(&ddi);
> } else {
> - cpumask_var_t wq_domain_mask;
> struct pci_probe_arg arg = { .ddi = &ddi };
>
> - if (!zalloc_cpumask_var(&wq_domain_mask, GFP_KERNEL)) {
> - error = -ENOMEM;
> - goto out;
> - }
> -
> INIT_WORK_ONSTACK(&arg.work, local_pci_probe_callback);
> -
> /*
> * The target election and the enqueue of the work must be within
> * the same RCU read side section so that when the workqueue pool
> @@ -402,12 +395,9 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
> * 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);
> + housekeeping_cpumask(HK_TYPE_DOMAIN));
> +
> if (cpu < nr_cpu_ids) {
> struct workqueue_struct *wq = pci_probe_wq;
>
> @@ -422,10 +412,9 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
> error = local_pci_probe(&ddi);
> }
>
> - free_cpumask_var(wq_domain_mask);
> destroy_work_on_stack(&arg.work);
> }
> -out:
> +
> dev->is_probed = 0;
> cpu_hotplug_enable();
> return error;
> --
> 2.51.1
>