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NAME | SYNOPSIS | DESCRIPTION | RETURN | ERRORS | SEE ALSO | AUTHOR | COLOPHON |
LIBPFM(3) Linux Programmer's Manual LIBPFM(3)
pfm_get_event_next - iterate over events
#include <perfmon/pfmlib.h>
int pfm_get_event_next(int idx);
Events are uniquely identified with opaque integer identifiers.
There is no guaranteed order within identifiers. Thus, to list all
the events, it is necessary to use iterators.
Events are grouped in tables within the library. A table usually
corresponds to a PMU model or family. The library contains support
for multiple PMU models, thus it has multiple tables. Based on the
host hardware and software environments, tables get activated when
the library is initialized via pfm_initialize(). Events from
activated tables are called active events. Events from non-activated
tables are called supported events.
Event identifiers are usually retrieved via pfm_find_event() or when
encoding events.
To iterate over a list of events for a given PMU model, all that is
needed is an initial identifier for the PMU. The first event
identifier is usually obtained via pfm_get_pmu_info().
The pfm_get_event_next() function returns the identifier of next
supported event after the one passed in idx. This iterator stops when
the last event for the PMU is passed as argument, in which case the
function returns -1.
void list_pmu_events(pfm_pmu_t pmu)
{
struct pfm_event_info info;
struct pfm_pmu_info pinfo;
int i, ret;
memset(&info, 0, sizeof(info));
memset(&pinfo, 0, sizeof(pinfo));
info.size = sizeof(info);
pinfo.size = sizeof(pinfo);
ret = pfm_get_pmu_info(pmu, &pinfo);
if (ret != PFM_SUCCESS)
errx(1, "cannot get pmu info");
for (i = pinfo.first_event; i != -1; i = pfm_get_event_next(i)) {
ret = pfm_get_event_info(i, &info);
if (ret != PFM_SUCCESS)
errx(1, "cannot get event info");
printf("%s Event: %s::%s\n",
pinfo.present ? "Active" : "Supported",
pinfo.name, info.name);
}
}
The function returns the identifier of the next supported event. It
returns -1 when the argument is already the last event for the PMU.
No error code, besides -1, is returned by this function.
pfm_find_event(3)
Stephane Eranian <eranian@gmail.com>
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COLOPHON (which is not part of the original manual page), send a mail
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September, 2009 LIBPFM(3)