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

["Mi, Dapeng" <dapeng1.mi@linux.intel.com>]

On 1/28/2025 12:26 AM, Peter Zijlstra wrote:
> 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@linux.intel.com>
>> ---
>>  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.

Sorry for late response since the Chinese new year holiday.

Sierra Forest is based on Crestmont instead of Skymont. The 3 new fixed
counters are introduced from Skymont and Darkmont inherits them. So these
attributes are named with "skt" suffix.


>