NAME

       libpfm_intel_adl_glc - support for Intel Alderlake Goldencove (P-Core) core PMU

SYNOPSIS

       #include <perfmon/pfmlib.h>

       PMU name: adl_glc
       PMU desc: Intel Alderlake Goldencove (P-core)

DESCRIPTION

       The  library  supports the Intel Alderlake Goldencove (P-Core) core PMU. It should be noted that this PMU
       model only covers each core's PMU and not the socket level PMU.  Because  the  processor  uses  a  hybrid
       architecture  with  a  P-Core  and  E-Core with a different PMU model, it may be necessary to force a PMU
       instance  name  to   get   the   desired   encoding.   For   instance,   to   encode   for   the   P-Core
       adl_glc::BR_INST_RETIRED and for the E-core adl_grt::BR_INST_RETIRED.

       On Adlerlake Goldencove (P-Core), the number of generic counters depends on the Hyperthreading (HT) mode.

       The pfm_get_pmu_info() function returns the maximum number of generic counters in num_cntrs.

MODIFIERS

       The following modifiers are supported on Intel SapphireRapid processors:

       u      Measure at user level which includes privilege levels 1, 2, 3. This corresponds to PFM_PLM3.  This
              is a boolean modifier.

       k      Measure at kernel level which includes privilege level 0. This corresponds to PFM_PLM0.  This is a
              boolean modifier.

       i      Invert  the  meaning  of  the  event.  The counter will now count cycles in which the event is not
              occurring. This is a boolean modifier

       e      Enable edge detection, i.e., count only when there is a state transition from no occurrence of the
              event to at least one occurrence. This modifier must be combined with a counter mask modifier  (m)
              with a value greater or equal to one.  This is a boolean modifier.

       c      Set  the  counter  mask  value. The mask acts as a threshold. The counter will count the number of
              cycles in which the number of occurrences of the event is greater or equal to the threshold.  This
              is an integer modifier with values in the range [0:255].

       intx   Monitor the event only when executing inside a transactional memory region (in tx). Event does not
              count otherwise. This is a boolean modifiers. Default value is 0.

       intxcp Do not count occurrences of the event when they are inside an aborted transactional memory region.
              This is a boolean modifier. Default value is 0.

       ldlat  Pass  a  latency threshold in core cycles to the MEM_TRANS_RETIRED:LOAD_LATENCY event.  This is an
              integer attribute that must be in the range [1:65535]. It is required for this event. The  library
              provides  a  set of presets for specific latencies, such as 128.  Note that the event must be used
              with precise sampling (PEBS).

FRONTEND_RETIRED event

       For Alderlake Goldencove (P-Core), the library uses the hardcoded bubble width and bubble length provided
       by Intel preset events.  It is not possible to tweak either the latency or the width via the library.

OFFCORE_RESPONSE events

       Intel Alderlake Goldencove (P-Core) supports two encodings for offcore_response events (0x2a,  0x2b).  In
       the  library,  these are called OCR0 and OCR1. The two encodings are equivalent. On Linux, the kernel can
       schedule any OCR encoding into any of the two OCR counters.  The offcore_response events are exposed as a
       normal events by the library. The extra settings are exposed as regular umasks. The library takes care of
       encoding the events according to the underlying kernel interface.

       On Intel Alderlake Goldencove (P-Core), the event is treated as a regular event with a flat set of umasks
       to choose from.  It is not possible to combine the various requests, supplier, snoop  bits  anymore.  The
       library offers the list of validated combinations as per Intel's official event list.

AUTHORS

       Stephane Eranian <eranian@gmail.com>

                                                 February, 2024                                        LIBPFM(3)