Re: [Experimental CPU Hotplug PATCH] - Move migrate_all_tasks to CPU_DEAD handling

[Nick Piggin <nickpiggin@yahoo.com.au>]

Nick Piggin wrote:
> Srivatsa Vaddagiri wrote:
> 
>> On Tue, Apr 06, 2004 at 10:28:53AM +1000, Nick Piggin wrote:
>>
>>> First of all, if you're proposing this stuff for inclusion, you
>>> should port it to the -mm tree, because I don't think Andrew
>>> will want any other scheduler work going in just now. It wouldn't
>>> be too hard.
>>
>>
>>
>> Will send out today a patch against latest -mm tree!
>>
>>
>>> I think my stuff is a bit orthogonal to what you're attempting.
>>> And they should probably work well together. My "lazy migrate"
>>> patch means the tasklist lock does not need to be held at all,
>>> only the dying runqueue's lock.
>>
>>
>>
>> Is there some place where I can download your patch (or is it in -mm 
>> tree)?
>>
>>
> 
> I have attached it (against 2.6.5-mm1). I haven't actually tested it
>  #ifdef CONFIG_SMP
> -	if (unlikely(task_running(rq, p) || cpu_is_offline(this_cpu)))
> +	if (unlikely(task_running(rq, p))
>  		goto out_activate;
>  
>  	new_cpu = cpu;
>  
> +#ifdef CONFIG_HOTPLUG_CPU
> +	if (unlikely(cpu_is_offline(cpu))) {
> +		/* Must lazy-migrate off this CPU */
> +		goto out_set_cpu;
> +	}
> +#endif
> +

Err, that should be:
#ifdef CONFIG_HOTPULG_CPU
	if (unlikely(cpu_is_offline(cpu))) {
		/* Must lazy-migrate off this CPU */
		new_cpu = go_away(p);
		goto out_set_cpu;
	}
#endif