Re: [PATCH -next RFC -v2 10/11] cpuset: use parse_cpulist for setting cpus.exclusive

[Waiman Long <llong@redhat.com>]

On 9/8/25 11:32 PM, Chen Ridong wrote:
> From: Chen Ridong <chenridong@huawei.com>
>
> Previous patches made parse_cpulist handle empty cpu mask input.
> Now use this helper for exclusive cpus setting. Also, compute_trialcs_xcpus
> can be called with empty cpus and handles it correctly.
>
> Signed-off-by: Chen Ridong <chenridong@huawei.com>
> ---
>   kernel/cgroup/cpuset.c | 25 +++++++++----------------
>   1 file changed, 9 insertions(+), 16 deletions(-)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index de61520f1e44..785a2740b0ea 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -2567,27 +2567,20 @@ static int update_exclusive_cpumask(struct cpuset *cs, struct cpuset *trialcs,
>   	bool force = false;
>   	int old_prs = cs->partition_root_state;
>   
> -	if (!*buf) {
> -		cpumask_clear(trialcs->exclusive_cpus);
> -		cpumask_clear(trialcs->effective_xcpus);
> -	} else {
> -		retval = cpulist_parse(buf, trialcs->exclusive_cpus);
> -		if (retval < 0)
> -			return retval;
> -	}
> +	retval = parse_cpuset_cpulist(buf, trialcs->exclusive_cpus);
> +	if (retval < 0)
> +		return retval;
>   
>   	/* Nothing to do if the CPUs didn't change */
>   	if (cpumask_equal(cs->exclusive_cpus, trialcs->exclusive_cpus))
>   		return 0;
>   
> -	if (*buf) {
> -		/*
> -		 * Reject the change if there is exclusive CPUs conflict with
> -		 * the siblings.
> -		 */
> -		if (compute_trialcs_excpus(trialcs, cs))
> -			return -EINVAL;
> -	}
> +	/*
> +	 * Reject the change if there is exclusive CPUs conflict with
> +	 * the siblings.
> +	 */
> +	if (compute_trialcs_excpus(trialcs, cs))
> +		return -EINVAL;
>   
>   	/*
>   	 * Check all the descendants in update_cpumasks_hier() if
Reviewed-by: Waiman Long <longman@redhat.com>