NAME | SYNOPSIS | DESCRIPTION | RETURN | ERRORS | AUTHOR | SEE ALSO | COLOPHON

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

NAME         top

       pfm_get_event_encoding - get raw event encoding

SYNOPSIS         top

       #include <perfmon/pfmlib.h>

       int pfm_get_event_encoding(const char *str,int dfl_plm, char **fstr, int *idx, uint64_t *code, int *count);

DESCRIPTION         top

       This function is used to retrieve the raw event encoding
       corresponding to the event string in str.  The string may contain
       unit masks and modifiers. The default privilege level mask is passed
       in dfl_plm.  It may be used depending on the event.

       This function is deprecated. It is superseded by
       pfm_get_os_event_encoding() where the OS is set to PFM_OS_NONE.
       Encoding is retrieve through the pfm_pmu_encode_arg_t structure.

       The following examples illustrates the transition:

          int i, count = 0;
          uint64_t *codes;

          ret = pfm_get_event_encoding("RETIRED_INSTRUCTIONS", PFM_PLM3, NULL, &codes, &count);
          if (ret != PFM_SUCCESS)
             err(1", cannot get encoding %s", pfm_strerror(ret));

          for(i=0; i < count; i++)
             printf("count[%d]=0x%"PRIx64"\n", i, codes[i]);

       is equivalent to:

          pfm_pmu_encode_arg_t arg;
          int i;

          memset(&arg, 0, sizeof(arg));
          arg.size = sizeof(arg);

          ret = pfm_get_os_event_encoding("RETIRED_INSTRUCTIONS", PFM_PLM3, PFM_OS_NONE, &arg);
          if (ret != PFM_SUCCESS)
             err(1", cannot get encoding %s", pfm_strerror(ret));

          for(i=0; i < arg.count; i++)
             printf("count[%d]=0x%"PRIx64"\n", i, arg.codes[i]);

          free(arg.codes);

       The encoding may take several 64-bit integers. The function can use the array passed in code if the number
       of entries passed in count is big enough. However, if both *codes is NULL and count
       is 0, the function allocates the memory necessary to store the encoding. It is up to the caller to
       eventually free the memory. The number of 64-bit entries in codes is reflected in *count upon
       return regardless of whether the codes was allocated or used as is. If the number of 64-bit integers is
       greater than one, then the order in which each component is returned is PMU-model specific. Refer to the PMU
       specific man page.

       The raw encoding means the encoding as mandated by the underlying PMU model. It may not be directly suitable
       to pass to a kernel API. You may want to use API-specific library calls to ensure the correct encoding is passed.

       If fstr is not NULL, it will point to the fully qualified event string upon successful return. The string
       contains the event name, any umask set, and the value of all the modifiers. It reflects what the encoding will
       actually measure. The function allocates the memory to store the string. The caller must eventually free the
       string.

       Here is a example of how this function could be used:
       #include <inttypes.h>
       #include <err.h>
       #include <perfmon/pfmlib.h>
       int main(int argc, char **argv)
       {
          uint64_t *codes 0;
          int count = 0;
          int ret;

          ret = pfm_initialize();
          if (ret != PFMLIB_SUCCESS)
             err(1", cannot initialize library %s", pfm_strerror(ret));

          ret = pfm_get_event_encoding("RETIRED_INSTRUCTIONS", PFM_PLM3, NULL, &codes, &count);
          if (ret != PFM_SUCCESS)
             err(1", cannot get encoding %s", pfm_strerror(ret));

          for(i=0; i < count; i++)
             printf("count[%d]=0x%"PRIx64"\n", i, codes[i]);

          free(codes);
          return 0;
       }

RETURN         top

       The function returns in *codes the encoding of the event and in
       *count the number of 64-bit integers to support that encoding. Upon
       success, PFM_SUCCESS is returned otherwise a specific error code is
       returned.

ERRORS         top

       PFM_ERR_TOOSMALL
              The code argument is too small for the encoding.

       PFM_ERR_INVAL
              The code or count argument is NULL.

       PFM_ERR_NOMEM
              Not enough memory.

       PFM_ERR_NOTFOUND
              Event not found.

       PFM_ERR_ATTR
              Invalid event attribute (unit mask or modifier)

       PFM_ERR_ATTR_VAL
              Invalid modifier value.

       PFM_ERR_ATTR_SET
              attribute already set, cannot be changed.

       PFM_ERR_ATTR_UMASK
              Missing unit mask.

       PFM_ERR_ATTR_FEATCOMB
              Unit masks or features cannot be combined into a single event.

AUTHOR         top

       Stephane Eranian <eranian@gmail.com>

SEE ALSO         top

       pfm_get_os_event_encoding(3)

COLOPHON         top

       This page is part of the perfmon2 (a performance monitoring library)
       project.  Information about the project can be found at 
       ⟨http://perfmon2.sourceforge.net/⟩.  If you have a bug report for this
       manual page, send it to perfmon2-devel@lists.sourceforge.net.  This
       page was obtained from the project's upstream Git repository 
       ⟨git://git.code.sf.net/p/perfmon2/libpfm4⟩ on 2017-03-13.  If you dis‐
       cover any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

                               September, 2009                     LIBPFM(3)