Alexey Klimov <aklimov@xxxxxxxxxx> writes: > The first section of comment seems problematic to me with regards to such move: > > * As this needs to hold the cpu maps lock it's impossible > * to call device_offline() because that ends up calling > * cpu_down() which takes cpu maps lock. cpu maps lock > * needs to be held as this might race against in kernel > * abusers of the hotplug machinery (thermal management). > > Cpu maps lock is released in cpu_maps_update_done() hence we will move > dev->offline out of cpu maps lock. Maybe I misunderstood the comment > and it relates to calling cpu_down_maps_locked() under lock to avoid > race? Yes, that's what I take from the comment, the cpu maps lock protects against racing hotplug operations.
