NAME

       pfm_get_pmu_info - get PMU information

SYNOPSIS

       #include <perfmon/pfmlib.h>

       int pfm_get_pmu_info(pfm_pmu_t pmu, pfm_pmu_info_t *info);

DESCRIPTION

       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:

              PFM_PMU_TYPE_UNKNOWN
                     The type of the PMU could not be determined.

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

              PFM_PMU_TYPE_UNCORE
                     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.

       nevents
              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.

       first_event
              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.

       num_cntrs
              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.

       num_fixed_cntrs
              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.

       max_encoding
              This field returns the number of event codes returned by pfm_get_event_encoding().

       is_present
              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

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

ERRORS

       PFMLIB_ERR_NOINIT
              Library has not been initialized properly.

       PFMLIB_ERR_NOTSUPP
              PMU model is not supported by the library.

       PFMLIB_ERR_INVAL
              The pmu argument is invalid or info is NULL or size is not zero.

SEE ALSO

       pfm_get_event_next(3)

AUTHOR

       Stephane Eranian <eranian@gmail.com>

                                                 December, 2009                                        LIBPFM(3)