Tribblix: manual page: cpc_walk_events

CPC_NPIC(3CPC) CPU Performance Counters Library Functions CPC_NPIC(3CPC)

NAME

cpc_npic, cpc_caps, cpc_cciname, cpc_cpuref, cpc_walk_events_all,
cpc_walk_generic_events_all, cpc_walk_events_pic,
cpc_walk_generic_events_pic, cpc_walk_attrs - determine CPU
performance counter configuration

SYNOPSIS

cc [ flag... ] file... -lcpc [ library... ]
#include <libcpc.h>

uint_t cpc_npic(cpc_t *cpc);

uint_t cpc_caps(cpc_t *cpc);

const char *cpc_cciname(cpc_t *cpc);

const char *cpc_cpuref(cpc_t *cpc);

void cpc_walk_events_all(cpc_t *cpc, void *arg,
void (*action)(void *arg, const char *event));

void cpc_walk_generic_events_all(cpc_t *cpc, void *arg,
void (*action)(void *arg, const char *event));

void cpc_walk_events_pic(cpc_t *cpc, uint_t picno, void *arg,
void (*action)(void *arg, uint_t picno, const char *event));

void cpc_walk_generic_events_pic(cpc_t *cpc, uint_t picno,
void *arg, void (*action)(void *arg, uint_t picno,
const char *event));

void cpc_walk_attrs(cpc_t *cpc, void *arg,
void (*action)(void *arg, const char *attr));

DESCRIPTION

The cpc_cciname() function returns a printable description of the
processor performance counter interfaces, for example, the string
UltraSPARC III+ & IV. This name should not be assumed to be the same
as the name the manufacturer might otherwise ascribe to the
processor. It simply names the performance counter interfaces as
understood by the system, and thus names the set of performance
counter events that can be described by that interface.

The cpc_cpuref() function returns a string that describes a reference
work that should be consulted to (allow a human to) understand the
semantics of the performance counter events that are known to the
system. The string returned might be substantially longer than 80
characters. Callers printing to a terminal might want to insert line
breaks as appropriate.

The cpc_npic() function returns the number of performance counters
accessible on the processor.

The cpc_caps() function returns a bitmap containing the bitwise
inclusive-OR of zero or more flags that describe the capabilities of
the processor. If CPC_CAP_OVERFLOW_INTERRUPT is present, the
processor can generate an interrupt when a hardware performance
counter overflows. If CPC_CAP_OVERFLOW_PRECISE is present, the
processor can determine precisely which counter overflowed, thereby
affecting the behavior of the overflow notification mechanism
described in cpc_bind_curlwp(3CPC).

The system maintains a list of performance counter events supported
by the underlying processor. Some processors are able to count all
events on all hardware counters, while other processors restrict
certain events to be counted only on specific hardware counters. The
system also maintains a list of processor-specific attributes that
can be used for advanced configuration of the performance counter
hardware. These functions allow applications to determine what events
and attributes are supported by the underlying processor. The
reference work pointed to by cpc_cpuref() should be consulted to
understand the reasons for and use of the attributes.

The cpc_walk_events_all() function calls the action function on each
element of a global event list. The action function is called with
each event supported by the processor, regardless of which counter is
capable of counting it. The action function is called only once for
each event, even if that event can be counted on more than one
counter.

The cpc_walk_events_pic() function calls the action function with
each event supported by the counter indicated by the picno argument,
where picno ranges from 0 to the value returned by cpc_npic().

The system maintains a list of platform independent performance
counter events known as generic events (see generic_events(3CPC)).

The cpc_walk_generic_events_all() function calls the action function
on each generic event available on the processor. The action function
is called for each generic event, regardless of which counter is
capable of counting it. The action function is called only once for
each event, even if that event can be counted on more than one
counter.

The cpc_walk_generic_events_pic() function calls the action function
with each generic event supported by the counter indicated by the
picno argument, where picno ranges from 0 to the value returned by
cpc_npic().

The system maintains a list of attributes that can be used to enable
advanced features of the performance counters on the underlying
processor. The cpc_walk_attrs() function calls the action function
for each supported attribute name. See the reference material as
returned by cpc_cpuref(3CPC) for the semantics use of attributes.

RETURN VALUES

The cpc_cciname() function always returns a printable description of
the processor performance counter interfaces.

The cpc_cpuref() function always returns a string that describes a
reference work.

The cpc_npic() function always returns the number of performance
counters accessible on the processor.

The cpc_caps() function always returns a bitmap containing the
bitwise inclusive-OR of zero or more flags that describe the
capabilities of the processor.

If the user-defined function specified by action is not called, the
cpc_walk_events_all(), cpc_walk_events_pic(), cpc_walk_attrs(),
cpc_walk_generic_events_pic(), and cpc_walk_generic_events_pic()
functions set errno to indicate the error.

ERRORS

The cpc_walk_events_all(), cpc_walk_events_pic(), cpc_walk_attrs(),
cpc_walk_generic_events_pic(), and cpc_walk_generic_events_pic()
functions will fail if:

ENOMEM
There is not enough memory available.