`pfm_get_event_encoding` ( 3 )

получить исходную кодировку событий (get raw event encoding)

Имя (Name)

pfm_get_event_encoding - get raw event encoding

Синопсис (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);

Описание (Description)

This function is used to retrieve the raw event encoding
       corresponding to the event string in str.  Only one event per
       call can be encoded. As such, str can contain only one symbolic
       event name.  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 It is superseded by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;
       }

Возврат (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 success, PFM_SUCCESS is returned otherwise a specific error
       code is returned.

Ошибки (Error)

PFM_ERR_TOOSMALL The code argument is too small for the encoding.

PFM_ERR_INVAL The code or count argument is NULL or the str contains more than one symbolic event.

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.