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

NAME

       pfm_get_event_encoding - get raw event encoding

SYNOPSIS

       #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

       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 It is superseded by pfm_get_os_event_encoding() where the OS is  set  to  PFM_OS_NONE.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"
", 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"
", 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 succesful 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"
", i, codes[i]);

	  free(codes);
	  return 0;
       }

RETURN

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

ERRORS

       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

       Stephane Eranian <eranian@gmail.com>

SEE ALSO

       pfm_get_os_event_encoding(3)

								  September, 2009							 LIBPFM(3)