On Thu, Jun 18 2026 at 18:06, Thomas Gleixner wrote: > On Thu, Jun 18 2026 at 11:11, Jing Wu wrote: >> Add CPUHP_AP_NO_HZ_FULL_DYING and CPUHP_AP_IRQ_AFFINITY_DYING to the >> cpuhp_state enum. These dying callbacks are invoked during CPU offline >> before the tick is stopped, enabling clean tick handover and managed >> IRQ migration when a CPU transitions between isolated and housekeeping >> states. >> >> The existing CPUHP_AP_IRQ_AFFINITY_ONLINE already handles managed IRQ >> restoration on CPU online. The new dying callback completes the pair, >> migrating managed interrupts away from the CPU before it goes down. > > What? They are migrated away today already when the CPU goes down unless > the CPU is the last one in the affinity set of the interrupt. So why do > you need a new step for something which already exists?
Aside of that these hotplug states are not used at all. So what is this patch for?
