Re: [PATCH 01/20] perf/x86/intel: Add PMU support for Clearwater Forest

[Peter Zijlstra]

On Thu, Jan 23, 2025 at 02:07:02PM +0000, Dapeng Mi wrote:
> From PMU's perspective, Clearwater Forest is similar to the previous
> generation Sierra Forest.
> 
> The key differences are the ARCH PEBS feature and the new added 3 fixed
> counters for topdown L1 metrics events.
> 
> The ARCH PEBS is supported in the following patches. This patch provides
> support for basic perfmon features and 3 new added fixed counters.
> 
> Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
> ---
>  arch/x86/events/intel/core.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
> index b140c1473a9d..5e8521a54474 100644
> --- a/arch/x86/events/intel/core.c
> +++ b/arch/x86/events/intel/core.c
> @@ -2220,6 +2220,18 @@ static struct extra_reg intel_cmt_extra_regs[] __read_mostly = {
>  	EVENT_EXTRA_END
>  };
>  
> +EVENT_ATTR_STR(topdown-fe-bound,       td_fe_bound_skt,        "event=0x9c,umask=0x01");
> +EVENT_ATTR_STR(topdown-retiring,       td_retiring_skt,        "event=0xc2,umask=0x02");
> +EVENT_ATTR_STR(topdown-be-bound,       td_be_bound_skt,        "event=0xa4,umask=0x02");
> +
> +static struct attribute *skt_events_attrs[] = {
> +	EVENT_PTR(td_fe_bound_skt),
> +	EVENT_PTR(td_retiring_skt),
> +	EVENT_PTR(td_bad_spec_cmt),
> +	EVENT_PTR(td_be_bound_skt),
> +	NULL,
> +};

The skt here is skymont, which is what Sierra Forest was based on, and
you just said that these counters are new with Darkmont, and as such the
lot should be called: dmt or whatever the proper trigraph is.