Re: Bulk CPU Hotplug (Was Re: [PATCH] Do not force shutdown/rebootto boot cpu.)

[Oleg Nesterov]

On 04/12, Robin Holt wrote:
>
> +void migrate_to_boot_cpu(void)
> +{
> +	/* The boot cpu is always logical cpu 0 */
> +	int reboot_cpu_id = 0;
> +
> +	/* Make certain the cpu I'm about to reboot on is online */
> +	if (!cpu_online(reboot_cpu_id))
> +		reboot_cpu_id = smp_processor_id();
> +
> +	/* Make certain I only run on the appropriate processor */
> +	set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));

This is only theoretical, but perhaps it makes sense to set
PF_THREAD_BOUND before set_cpus_allowed_ptr() ? To prevent the
race with another thread doing sched_setaffinity().

Oleg.

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