> IRQ_NOBALANCING is not preventing cpu unplug. It moves the affinity to the > next CPU, but the check in NMI watchdog for CPU == 0 would not longer > work. That cannot happen right now because cpu_disable() on both i386/x86-64 reject CPU #0. So just setting IRQ_NOBALANCING is sufficient and both do that already. I was wrong earlier in being concerned about this. > int tick_do_broadcast(cpumask_t mask) > @@ -137,6 +147,7 @@ int tick_do_broadcast(cpumask_t mask) > cpu_clear(cpu, mask); > td = &per_cpu(tick_cpu_device, cpu); > td->evtdev->event_handler(td->evtdev); > + tick_broadcast_account(cpu); That would not handle the case with a single CPU running only irq 0 but not broadcasting I think. I believe ftp://ftp.firstfloor.org/pub/ak/x86_64/quilt/patches/fix-watchdog is the correct fix -Andi - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
