perfmon2
   the hardware-based performance monitoring interface for Linux
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Documentation
libpfm manual

NAME

libpfm_x86_64 - support for AMD64 processors

SYNOPSIS

#include <perfmon/pfmlib.h>
#include <perfmon/pfmlib_amd64.h>

DESCRIPTION

The libpfm library provides full support for the AMD64 processor family 15 and 16 when running in either 32 or 64 bit mode. The interface is defined in pfmlib_amd64.h. It consists of a set of functions and structures which describe and allow access to the AMD64 PMU features. Note that it does not support Intel EM64T processors.

When AMD64 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 AMD64 processor-specific input arguments are described in the pfmlib_amd64_input_param_t structure and the output parameters in pfmlib_amd64_output_param_t. They are defined as follows:

typedef struct {
        unsigned int    cnt_mask;
        unsigned int    flags;
} pfmlib_amd64_counter_t;

typedef struct {
        pfmlib_amd64_counter_t     pfp_amd64_counters[PMU_GEN_X86_64_NUM_COUNTERS];
        uint64_t                   reserved[4];
} pfmlib_amd64_input_param_t;

typedef struct {
        uint64_t        reserved[8];
} pfmlib_amd64_output_param_t;

The X86-64 processor provides a few additional per-event features for counters: thresholding, inversion, edge detection. They can be set using the pfp_amd64_counters data structure for each event. The flags field can be initialized as follows:

  • PFMLIB_AMD64_SEL_INV: Inverse the results of the cnt_mask comparison when set
  • PFMLIB_AMD64_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.

ERRORS

Refer to the description of pfm_dispatch_events() for errors.

SEE ALSO

pfm_dispatch_events() and set of examples shipped with the library

AUTHOR

Stephane Eranian


This document was created by man2html, using the manual pages.
Time: 16:57:22 GMT, October 27, 2007