[RFC PATCH v3 04/10] sched/core: Dont allow to use CPU marked as paravirt

[Shrikanth Hegde]

On 9/11/25 10:46 AM, K Prateek Nayak wrote:
> Hello Shrikanth,
> 

Hi Prateek, Thanks for looking into this.

> On 9/10/2025 11:12 PM, Shrikanth Hegde wrote:
>> @@ -2462,8 +2462,13 @@ static inline bool is_cpu_allowed(struct task_struct *p, int cpu)
>>   		return cpu_online(cpu);
>>   
>>   	/* Non kernel threads are not allowed during either online or offline. */
>> -	if (!(p->flags & PF_KTHREAD))
>> -		return cpu_active(cpu);
>> +	if (!(p->flags & PF_KTHREAD)) {
>> +		/* A user thread shouldn't be allowed on a paravirt cpu */
>> +		if (is_cpu_paravirt(cpu))
>> +			return false;
>> +		else
> 
> nit. redundant "else". I think this can be simplified as:
>

alright.
>      return !is_cpu_paravirt(cpu) && cpu_active(cpu);
> 
>> +			return cpu_active(cpu);
>> +	}
>