Re: [PATCH v6 7/8] cgroup/cpuset: Defer housekeeping_update() calls from CPU hotplug to workqueue

[Waiman Long <longman@redhat.com>]

On 3/4/26 6:07 AM, Jon Hunter wrote:
>
> On 04/03/2026 03:58, Waiman Long wrote:
>
> ...
>
>> It looks that -EBUSY was returned when the script tries to online/ 
>> offline a CPU. I ran a simple script to repetitively doing offline/ 
>> online operation and couldn't reproduce the problem. I don't have 
>> access to the tegra board that you use for testing. Would you mind 
>> trying out the following patch to see if it can get rid of the problem.
>>
>> Thanks,
>> Longman
>>
>> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
>> index e200de7c60b6..5a5953fb391c 100644
>> --- a/kernel/cgroup/cpuset.c
>> +++ b/kernel/cgroup/cpuset.c
>> @@ -3936,8 +3936,10 @@ static void cpuset_handle_hotplug(void)
>>           * previously queued work. Since hk_sd_workfn() doesn't use 
>> the work
>>           * item at all, this is not a problem.
>>           */
>> -       if (update_housekeeping || force_sd_rebuild)
>> -               queue_work(system_unbound_wq, &hk_sd_work);
>> +       if (force_sd_rebuild)
>> +               rebuild_sched_domains_cpuslocked();
>> +       if (update_housekeeping)
>> +               queue_work(system_dfl_wq, &hk_sd_work);
>>
>>          free_tmpmasks(ptmp);
>>   }
>>
>>
>
> Yes that did the trick. Works for me. Feel free to add my ...
>
> Tested-by: Jon Hunter <jonathanh@nvidia.com> 

Thanks for the confirmation.

Cheers,
Longman