After change of housekeeping_cpumask(HK_TYPE_MANAGED_IRQ) during runtime managed interrupts continue to run on isolated CPUs. Dynamic CPUs isolation is complex task. One of approaches is: 1. Set affected CPUs offline and disable relevant interrupts 2. Change housekeeping_cpumask 3. Set affected CPUs online and enable relevant interrupts irq_restore_affinity_of_irq() restores managed interrupts during complex CPU hotplug process of bringing back a CPU online. Leave the interrupts disabled those affinity doesn't intersect with new housekeeping_cpumask thereby ensuring isolation of the CPU from managed intrrupts. Signed-off-by: Costa Shulyupin <costa.shul@xxxxxxxxxx> --- kernel/irq/cpuhotplug.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index ec2cdcd20bee..839d3e879c0d 100644 --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -218,6 +218,9 @@ static void irq_restore_affinity_of_irq(struct irq_desc *desc, unsigned int cpu) if (desc->istate & IRQS_SUSPENDED) return; + if (!cpumask_intersects(affinity, housekeeping_cpumask(HK_TYPE_MANAGED_IRQ))) + return; + if (irqd_is_managed_and_shutdown(data)) irq_startup(desc, IRQ_RESEND, IRQ_START_COND); -- 2.47.0
