NAME
libpfm_core - support for Intel Core processor family
SYNOPSIS
#include <perfmon/pfmlib.h>
#include <perfmon/pfmlib_core.h>
DESCRIPTION
The libpfm library provides full support for the Intel Core processor
family, including the Core 2 Duo series. The interface is defined in
pfmlib_core.h. It consists of a set of functions and structures which
describe and allow access to the Intel Core processors specific PMU
features.
When Intel Core processor specific features are needed to support a
measurement, their descriptions must be passed as model-specific input
arguments to the pfm_dispatch_events call. The Intel Core
processors specific input arguments are described in the
pfmlib_core_input_param_t structure and the output parameters in
pfmlib_core_output_param_t. They are defined as follows:
typedef struct {
unsigned int cnt_mask;
unsigned int flags;
} pfmlib_core_counter_t;
typedef struct {
unsigned int pebs_used;
} pfmlib_core_pebs_t;
typedef struct {
pfmlib_core_counter_t pfp_core_counters[PMU_CORE_NUM_COUNTERS];
pfmlib_core_pebs_t pfp_core_pebs;
uint64_t reserved[4];
} pfmlib_core_input_param_t;
typedef struct {
uint64_t reserved[8];
} pfmlib_core_output_param_t;
The Intel Core processor provides a few additional per-event features
for counters: thresholding, inversion, edge detection. They can be set
using the pfp_core_counters data structure for each event. The flags
field can be initialized as follows:
PFMLIB_CORE_SEL_INV
Inverse the results of the cnt_mask comparison when set
PFMLIB_CORE_SEL_EDGE
Enables edge detection of events.
The cnt_mask field contains is used to set the event threshold. The
value of the counter is incremented each time the number of occurrences
per cycle of the event is greater or equal to the value of the field.
When zero all occurrences are counted.
Support for Precise-Event Based Sampling (PEBS)
The library can be used to setup the PMC registers when using PEBS. In
this case, the pfp_core_pebs structure must be used and the pebs_used
field must be set to 1. When using PEBS, it is not possible to use more
than one event.
Support for Intel Core 2 Duo processors
The Intel Core 2 Duo processors are based on the Intel Core micro-
architecture. They implement the Intel architectural PMU and some
extensions such as PEBS. They support all the architectural events and
a lot more Core 2 specific events. The library auto-detects the
processor and provides access to Core 2 events whenever possible.
ERRORS
Refer to the description of pfm_dispatch_events() for errors.
SEE ALSO
pfm_dispatch_events(3) and set of examples shipped with the library
AUTHOR
Stephane Eranian <eranian@hpl.hp.com>
November, 2006 LIBPFM(3)