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

On Thu, Jan 08, 2026 at 12:30:13AM +0100, Frederic Weisbecker wrote:

Le Wed, Jan 07, 2026 at 01:05:34PM -0600, Bjorn Helgaas a écrit :

quoted

On Thu, Jan 01, 2026 at 11:13:26PM +0100, Frederic Weisbecker wrote:

quoted

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 (local)

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.

I see. I can't drop my change, otherwise my series alone could crash
dereferencing garbage. But Jinhui's series removes the need for my
changes.

So an unpleasant conflict will happen in -next (and if everything
goes well, further in next merge window) and it should be resolved
with simply ignoring my changes and only apply those of Jinhui.

I don't want to derail your series, and I don't think you need to
change anything right now.  Jinhui's series is early and might not be
ready to merge until after yours, which should be fine.

Bjorn