Re: [PATCH 01/33] PCI: Prepare to protect against concurrent isolated cpuset change

Bjorn Helgaas
2026-01-07T19:05:35Z

[+cc Jinhui]

On Thu, Jan 01, 2026 at 11:13:26PM +0100, Frederic Weisbecker wrote:
> 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 <frederic@kernel.org>

Just FYI, Jinhui posted a series that touches this same code and might
need some coordination:

https://lore.kernel.org/r/20260107175548.1792-1-guojinhui.liam@bytedance.com

IIUC, Jinhui's series adds some more NUMA smarts in the driver core
sync probing path and removes corresponding NUMA code from the PCI
core probe path.

Bjorn