Re: [PATCH RESEND v10] sched/deadline: support dl task migration during cpu hotplug

From: Wanpeng Li
Date: Mon Mar 16 2015 - 19:19:23 EST


Hi Ingo,
On Mon, Mar 16, 2015 at 04:01:02PM +0100, Ingo Molnar wrote:
>> +
>> + /*
>> + * If cannot preempt any rq, fallback to pick any
>> + * online cpu.
>
>s/If cannot/If we cannot
>s/fallback/fall back

Will do.

>
>> + */
>> + fallback = true;
>> + cpu = cpumask_any_and(cpu_active_mask,
>> + tsk_cpus_allowed(p));
>
>shouldn't be on separate lines - but this is also a sign that the guts

Otherwise there is a "WARNING: line over 80 characters".

>of this new code should be in a helper function, not inside several
>layers of branches.

Do you mean the whole patch should be in a helper function?

>
>> + if (cpu >= nr_cpu_ids) {
>> + if (dl_bandwidth_enabled()) {
>> + /*
>> + * Fail to find any suitable cpu.
>> + * The task will never come back!
>> + */
>> + WARN_ON(1);
>
>Can this condition happen to users with a non-buggy kernel?

What do you prefer? ;-)

Regards,
Wanpeng Li

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