LIBPFM(3)                 Linux Programmer's Manual                LIBPFM(3)

NAME         top

       pfm_get_pmu_info - get PMU information

SYNOPSIS         top

       #include <perfmon/pfmlib.h>

       int pfm_get_pmu_info(pfm_pmu_t pmu, pfm_pmu_info_t *info);

DESCRIPTION         top

       This function returns in info information about a PMU model
       designated by its identifier in pmu.

       The pfm_pmu_info structure is defined as follows:
       typedef struct {
               const char              *name;
               const char              *desc;
               pfm_pmu_t               pmu;
               pfm_pmu_type_t          type;
               int                     size;
               int                     nevents;
               int                     first_event;
               int                     max_encoding;
               int                     num_cntrs;
               int                     num_fixed_cntrs;
               struct {
                       int             is_present:1;
                       int             is_arch_default:1;
                       int             is_core:1;
                       int             is_uncore:1;
                       int             reserved:28;
       } pfm_pmu_info_t;

       The fields of this structure are defined as follows:

       name   This is the symbolic name of the PMU. This name can be used as
              a prefix in an event string. This is a read-only string.

       desc   This is the description of PMU. This is a read-only string.

       pmu    This is the unique PMU identification code. It is identical to
              the value passed in pmu and it provided only for completeness.

       type   This field contains the type of the PMU. The following types
              are defined:

                     The type of the PMU could not be determined.

                     This field is set to one when the PMU is implemented by
                     the processor core.

                     This field is set to one when the PMU is implemented on
                     the processor die but at the socket level, i.e.,
                     capturing events for all cores.

              This is the number of available events for this PMU model
              based on the host processor. It is only valid if the
              is_present field is set to 1. Event identifiers are not
              guaranteed contiguous. In other words, it is not because
              nevents is equal to 100, that event identifiers go from 0 to
              99. The iterator function pfm_get_event_next() must be used to
              go from one identifier to the next.

              This field returns the opaque index of the first event for
              this PMU model. The index can be used with
              pfm_get_event_info() or pfm_get_event_next() functions.  In
              case no event is available, this field contains -1.

              This field contains the number of generic counters supported
              by the PMU.  A counter is generic if it can count more than
              one event. When it is not possible to determine the number of
              generic counters, this field contains -1.

              This field contains the number of fixed counters supported by
              the PMU.  A counter is fixed if it hardwired to count only one
              event. When it is not possible to determine the number of
              generic counters, this field contains -1.

       size   This field contains the size of the struct passed. This field
              is used to provide for extensibility of the struct without
              compromising backward compatibility.  The value should be set
              to sizeof(pfm_pmu_info_t). If instead, a value of 0 is
              specified, the library assumes the struct passed is identical
              to the first ABI version which size is PFM_PMU_INFO_ABI0.
              Thus, if fields were added after the first ABI, they will not
              be set by the library. The library does check that bytes
              beyond what is implemented are zeroes.

              This field returns the number of event codes returned by

              This field is set to one is the PMU model has been detected on
              the host system.

       is_dfl This field is set to one if the PMU is the default PMU for
              this architecture.  Otherwise this field is zero.

RETURN         top

       If successful, the function returns PFM_SUCCESS and PMU information
       in info, otherwise it returns an error code.

ERRORS         top

              Library has not been initialized properly.

              PMU model is not supported by the library.

              The pmu argument is invalid or info is NULL or size is not

SEE ALSO         top


AUTHOR         top

       Stephane Eranian <>

COLOPHON         top

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                               December, 2009                      LIBPFM(3)