Re: [PATCH v2 2/2] powercap/intel_rapl: Fix the energy-pkg event for AMD CPUs

[Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>]

Hello Rafael,

On 8/2/2024 6:05 PM, Rafael J. Wysocki wrote:
> On Tue, Jul 30, 2024 at 6:53 AM Dhananjay Ugwekar
> <Dhananjay.Ugwekar@amd.com> wrote:
>>
>> After commit ("x86/cpu/topology: Add support for the AMD 0x80000026 leaf"),
>> on AMD processors that support extended CPUID leaf 0x80000026, the
>> topology_logical_die_id() macros, no longer returns package id, instead it
>> returns the CCD (Core Complex Die) id. This leads to the energy-pkg
>> event scope to be modified to CCD instead of package.
>>
>> For more historical context, please refer to commit 32fb480e0a2c
>> ("powercap/intel_rapl: Support multi-die/package"), which initially changed
>> the RAPL scope from package to die for all systems, as Intel systems
>> with Die enumeration have RAPL scope as die, and those without die
>> enumeration are not affected. So, all systems(Intel, AMD, Hygon), worked
>> correctly with topology_logical_die_id() until recently, but this changed
>> after the "0x80000026 leaf" commit mentioned above.
>>
>> Future multi-die Intel systems will have package scope RAPL counters,
>> but they will be using TPMI RAPL interface, which is not affected by
>> this change.
>>
>> Replacing topology_logical_die_id() with topology_physical_package_id()
>> conditionally only for AMD and Hygon fixes the energy-pkg event.
>>
>> On an AMD 2 socket 8 CCD Zen4 server:
>>
>> Before:
>>
>> linux$ ls /sys/class/powercap/
>> intel-rapl      intel-rapl:4    intel-rapl:8:0  intel-rapl:d
>> intel-rapl:0    intel-rapl:4:0  intel-rapl:9    intel-rapl:d:0
>> intel-rapl:0:0  intel-rapl:5    intel-rapl:9:0  intel-rapl:e
>> intel-rapl:1    intel-rapl:5:0  intel-rapl:a    intel-rapl:e:0
>> intel-rapl:1:0  intel-rapl:6    intel-rapl:a:0  intel-rapl:f
>> intel-rapl:2    intel-rapl:6:0  intel-rapl:b    intel-rapl:f:0
>> intel-rapl:2:0  intel-rapl:7    intel-rapl:b:0
>> intel-rapl:3    intel-rapl:7:0  intel-rapl:c
>> intel-rapl:3:0  intel-rapl:8    intel-rapl:c:0
>>
>> After:
>>
>> linux$ ls /sys/class/powercap/
>> intel-rapl  intel-rapl:0  intel-rapl:0:0  intel-rapl:1  intel-rapl:1:0
>>
>> Only one sysfs entry per-event per-package is created after this change.
>>
>> Fixes: 63edbaa48a57 ("x86/cpu/topology: Add support for the AMD 0x80000026 leaf")
>> Reported-by: Michael Larabel <michael@michaellarabel.com>
>> Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
>> Reviewed-by: Zhang Rui <rui.zhang@intel.com>
>> ---
>> Changes in v2:
>> * Updated scope description comment, commit log
>> * Rename rapl_pmu_is_pkg_scope() to rapl_msrs_are_pkg_scope()
>> * Check topology_logical_(die/package)_id return value
> 
> This patch does not depend on the first one in the series if I'm not
> mistaken, in which case I can pick it up separately if you want me to
> do that, so please let me know.

Sorry for the late reply, was out sick,

Yes, please pick this patch separately, it is independent from the first one.

Thanks,
Dhananjay

> 
> Thanks!
> 
>> ---
>>  drivers/powercap/intel_rapl_common.c | 34 ++++++++++++++++++++++++----
>>  1 file changed, 30 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c
>> index 3cffa6c79538..4bc56acb99d6 100644
>> --- a/drivers/powercap/intel_rapl_common.c
>> +++ b/drivers/powercap/intel_rapl_common.c
>> @@ -2128,6 +2128,21 @@ void rapl_remove_package(struct rapl_package *rp)
>>  }
>>  EXPORT_SYMBOL_GPL(rapl_remove_package);
>>
>> +/*
>> + * RAPL Package energy counter scope:
>> + * 1. AMD/HYGON platforms use per-PKG package energy counter
>> + * 2. For Intel platforms
>> + *     2.1 CLX-AP platform has per-DIE package energy counter
>> + *     2.2 Other platforms that uses MSR RAPL are single die systems so the
>> + *          package energy counter can be considered as per-PKG/per-DIE,
>> + *          here it is considered as per-DIE.
>> + *     2.3 New platforms that use TPMI RAPL doesn't care about the
>> + *         scope because they are not MSR/CPU based.
>> + */
>> +#define rapl_msrs_are_pkg_scope()                              \
>> +       (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||  \
>> +        boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
>> +
>>  /* caller to ensure CPU hotplug lock is held */
>>  struct rapl_package *rapl_find_package_domain_cpuslocked(int id, struct rapl_if_priv *priv,
>>                                                          bool id_is_cpu)
>> @@ -2135,8 +2150,14 @@ struct rapl_package *rapl_find_package_domain_cpuslocked(int id, struct rapl_if_
>>         struct rapl_package *rp;
>>         int uid;
>>
>> -       if (id_is_cpu)
>> -               uid = topology_logical_die_id(id);
>> +       if (id_is_cpu) {
>> +               uid = rapl_msrs_are_pkg_scope() ?
>> +                     topology_physical_package_id(id) : topology_logical_die_id(id);
>> +               if (uid < 0) {
>> +                       pr_err("topology_logical_(package/die)_id() returned a negative value");
>> +                       return ERR_PTR(-EINVAL);
>> +               }
>> +       }
>>         else
>>                 uid = id;
>>
>> @@ -2168,9 +2189,14 @@ struct rapl_package *rapl_add_package_cpuslocked(int id, struct rapl_if_priv *pr
>>                 return ERR_PTR(-ENOMEM);
>>
>>         if (id_is_cpu) {
>> -               rp->id = topology_logical_die_id(id);
>> +               rp->id = rapl_msrs_are_pkg_scope() ?
>> +                        topology_physical_package_id(id) : topology_logical_die_id(id);
>> +               if ((int)(rp->id) < 0) {
>> +                       pr_err("topology_logical_(package/die)_id() returned a negative value");
>> +                       return ERR_PTR(-EINVAL);
>> +               }
>>                 rp->lead_cpu = id;
>> -               if (topology_max_dies_per_package() > 1)
>> +               if (!rapl_msrs_are_pkg_scope() && topology_max_dies_per_package() > 1)
>>                         snprintf(rp->name, PACKAGE_DOMAIN_NAME_LENGTH, "package-%d-die-%d",
>>                                  topology_physical_package_id(id), topology_die_id(id));
>>                 else
>> --
>> 2.43.0
>>
>>