Re: [patch 2/5] x86_64: CPU hotplug support.

From: Zwane Mwaikambo
Date: Thu Jun 02 2005 - 15:39:13 EST


On Thu, 2 Jun 2005, Ashok Raj wrote:

> @@ -445,8 +477,10 @@ void __cpuinit start_secondary(void)
> /*
> * Allow the master to continue.
> */
> + lock_ipi_call_lock();
> cpu_set(smp_processor_id(), cpu_online_map);
> mb();
> + unlock_ipi_call_lock();

What's that? Is this another smp_call_function race workaround? I thought
there was an additional patch to avoid the broadcast.

> +#include <asm/nmi.h>
> +/* We don't actually take CPU down, just spin without interrupts. */
> +static inline void play_dead(void)
> +{
> + idle_task_exit();
> + mb();
> + /* Ack it */
> + __get_cpu_var(cpu_state) = CPU_DEAD;
> +
> + local_irq_disable();
> + while (1)
> + safe_halt();
> +}

Might as well drop the local_irq_disable since safe_halt enables
interrupts.

Zwane

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