Re: [PATCH] x86/topology: Document cpu_llc_id

From: Peter Zijlstra
Date: Wed Sep 07 2016 - 06:36:58 EST


On Wed, Sep 07, 2016 at 11:22:19AM +0200, Borislav Petkov wrote:
> From: Borislav Petkov <bp@xxxxxxx>
>
> It means different things on Intel and AMD so write it down so that
> there's no confusion.
>
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> Documentation/x86/topology.txt | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/x86/topology.txt b/Documentation/x86/topology.txt
> index 06afac252f5b..7a5485730476 100644
> --- a/Documentation/x86/topology.txt
> +++ b/Documentation/x86/topology.txt
> @@ -63,6 +63,12 @@ The topology of a system is described in the units of:
> The maximum possible number of packages in the system. Helpful for per
> package facilities to preallocate per package information.
>
> + - cpu_llc_id:
> +
> + A per-CPU variable containing:
> + - On Intel, the first APIC ID of the list of CPUs sharing the Last Level
> + Cache
> + - On AMD, the Node ID containing the Last Level Cache.

And there are no AMD parts where there are multiple LLCs on a Node? Like
where there isn't an L3 and the L2 is only per cluster?