Re: [PATCH 2/2] perf/x86/rapl: Fix the energy-pkg event for AMD CPUs

From: Dhananjay Ugwekar
Date: Fri May 03 2024 - 06:07:23 EST


Hi Ingo,

On 5/3/2024 3:24 PM, Ingo Molnar wrote:
>
> * Dhananjay Ugwekar <Dhananjay.Ugwekar@xxxxxxx> wrote:
>
>> After commit ("x86/cpu/topology: Add support for the AMD 0x80000026 leaf"),
>> on AMD processors that support extended CPUID leaf 0x80000026, the
>> topology_die_cpumask() and topology_logical_die_id() macros, no longer
>> return the package cpumask and package id, instead they return the CCD
>> (Core Complex Die) mask and id respectively. This leads to the energy-pkg
>> event scope to be modified to CCD instead of package.
>>
>> Replacing these macros with their package counterparts fixes the
>> energy-pkg event for AMD CPUs.
>>
>> However due to the difference between the scope of energy-pkg event for
>> Intel and AMD CPUs, we have to replace these macros conditionally only for
>> AMD CPUs.
>>
>> On a 12 CCD 1 Package AMD Zen4 Genoa machine:
>>
>> Before:
>> $ cat /sys/devices/power/cpumask
>> 0,8,16,24,32,40,48,56,64,72,80,88.
>>
>> The expected cpumask here is supposed to be just "0", as it is a package
>> scope event, only one CPU will be collecting the event for all the CPUs in
>> the package.
>>
>> After:
>> $ cat /sys/devices/power/cpumask
>> 0
>>
>> Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@xxxxxxx>
>> Fixes: 63edbaa48a57 ("x86/cpu/topology: Add support for the AMD 0x80000026 leaf")
>> ---
>> arch/x86/events/rapl.c | 30 ++++++++++++++++++++++++++----
>> 1 file changed, 26 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/x86/events/rapl.c b/arch/x86/events/rapl.c
>> index 46e673585560..d77bf7959a43 100644
>> --- a/arch/x86/events/rapl.c
>> +++ b/arch/x86/events/rapl.c
>> @@ -102,6 +102,10 @@ static struct perf_pmu_events_attr event_attr_##v = { \
>> .event_str = str, \
>> };
>>
>> +#define rapl_pmu_is_pkg_scope() \
>> + (boot_cpu_data.x86_vendor == X86_VENDOR_AMD || \
>> + boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
>> +
>> struct rapl_pmu {
>> raw_spinlock_t lock;
>> int n_active;
>> @@ -139,9 +143,21 @@ static unsigned int rapl_cntr_mask;
>> static u64 rapl_timer_ms;
>> static struct perf_msr *rapl_msrs;
>>
>> +static inline unsigned int get_rapl_pmu_idx(int cpu)
>> +{
>> + return rapl_pmu_is_pkg_scope() ? topology_logical_package_id(cpu) :
>> + topology_logical_die_id(cpu);
>> +}
>> +
>> +static inline cpumask_t *get_rapl_pmu_cpumask(int cpu)
>> +{
>> + return rapl_pmu_is_pkg_scope() ? topology_core_cpumask(cpu) :
>> + topology_die_cpumask(cpu);
>> +}
>
> Note that this breaks the build with this config:
>
> https://download.01.org/0day-ci/archive/20240503/202405030828.RgFuznL9-lkp@xxxxxxxxx/config
>
> I've removed the commit from perf/core for now.

Sure, will fix this in v2.

Regards,
Dhananjay

>
> Thanks,
>
> Ingo