Re: [PATCH v2.1 2/2] x86/Documentation: Add documentation about cluster

From: Bagas Sanjaya
Date: Fri Apr 14 2023 - 22:24:44 EST


On 4/14/23 10:17, K Prateek Nayak wrote:
> + - cluster_id:
> +
> + A per-CPU variable containing:
> +
> + - Upper bits extracted from the APIC ID. CPUs which have the same value
> + in these bits share an L2 and have the same cluster_id.
> +
> + CPUs for which cluster information is unavailable will show 65535
> + (BAD_APICID) as the cluster_id.

"... return cluster_id of 65535 (BAD_APICID)."

> The number of online threads is also printed in /proc/cpuinfo "siblings."
>
> + - topology_cluster_cpumask():
> +
> + The cpumask contains all online threads in the cluster to which a thread
> + belongs.
> +

Looks OK.

> The physical package ID to which a thread belongs.
>
> + - topology_cluster_id();
> +
> + The ID of the cluster to which a thread belongs.
> +

Looks OK.

Thanks.

--
An old man doll... just what I always wanted! - Clara