Re: [PATCH] rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle()

From: Joel Fernandes
Date: Tue Aug 29 2023 - 06:13:53 EST




> On Aug 29, 2023, at 5:24 AM, Frederic Weisbecker <frederic@xxxxxxxxxx> wrote:
>
> On Mon, Aug 28, 2023 at 05:51:09PM -0400, Joel Fernandes wrote:
>> I think the issue is the loop later in the function does
>> not try to toggle cpus that came online too late.
>>
>> So it does not test offloading on all CPUs just because max got updated too
>> late.
>
> Right, and therefore for_each_possible_cpu() or for_each_present_cpu()
> should be fine to iterate since it's ok to try to toggle an offline CPU.

Ah I see what you mean, sounds good.

>
>>
>> One fix could be to periodically check in the loop if a new cpu at maxcpu + 1
>> ever got onlined. If it did, update the maxcpu.
>
> Is it worth the complication though?

Probably not and so your suggestion sounds fine.

Thanks!

- Joel


>
> Thanks.
>
>>
>> Thanks.
>>
>>
>>>
>>> Thanks.