Re: [RFC PATCH 3/3] rseq: extend struct rseq with numa node id

[Peter Zijlstra]

On Thu, Feb 03, 2022 at 02:38:53PM -0500, Mathieu Desnoyers wrote:
> +static int rseq_reset_rseq_cpu_node_id(struct task_struct *t)
>  {
> -	u32 cpu_id_start = 0, cpu_id = RSEQ_CPU_ID_UNINITIALIZED;
> +	u32 cpu_id_start = 0, cpu_id = RSEQ_CPU_ID_UNINITIALIZED, node_id = 0;
>  
>  	/*
>  	 * Reset cpu_id_start to its initial state (0).
> @@ -124,6 +126,11 @@ static int rseq_reset_rseq_cpu_id(struct task_struct *t)
>  	 */
>  	if (put_user(cpu_id, &t->rseq->cpu_id))
>  		return -EFAULT;
> +	/*
> +	 * Reset node_id to its initial state (0).
> +	 */
> +	if (put_user(node_id, &t->rseq->node_id))
> +		return -EFAULT;

Why 0 vs -1 ?