pfm_get_event_next(3) — Linux manual page


LIBPFM(3)               Linux Programmer's Manual              LIBPFM(3)

NAME         top

       pfm_get_event_next - iterate over events

SYNOPSIS         top

       #include <perfmon/pfmlib.h>

       int pfm_get_event_next(int idx);

DESCRIPTION         top

       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",

RETURN         top

       The function returns the identifier of the next supported event.
       It returns -1 when the argument is already the last event for the

ERRORS         top

       No error code, besides -1, is returned by this function.

SEE ALSO         top


AUTHOR         top

       Stephane Eranian <>

COLOPHON         top

       This page is part of the perfmon2 (a performance monitoring
       library) project.  Information about the project can be found at
       ⟨⟩.  If you have a bug report for
       this manual page, send it to  This page was obtained
       from the project's upstream Git repository
       ⟨git:// perfmon2-libpfm4⟩ on
       2023-06-23.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-06-07.)  If you
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                             September, 2009                   LIBPFM(3)

Pages that refer to this page: pfm_get_pmu_info(3)