pfm_get_event_encoding(3)

1LIBPFM(3)                  Linux Programmer's Manual                 LIBPFM(3)
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NAME

6       pfm_get_event_encoding - get raw event encoding
7

SYNOPSIS

9       #include <perfmon/pfmlib.h>
10
11       int pfm_get_event_encoding(const char *str,int dfl_plm, char **fstr, int *idx, uint64_t *code, int *count);
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13

DESCRIPTION

15       This  function is used to retrieve the raw event encoding corresponding
16       to the event string in str.  The string may contain unit masks and mod‐
17       ifiers.  The default privilege level mask is passed in dfl_plm.  It may
18       be used depending on the event.
19
20       This    function    is    deprecated.    It    is     superseded     by
21       pfm_get_os_event_encoding()  where the OS is set to PFM_OS_NONE. Encod‐
22       ing is retrieve through the pfm_pmu_encode_arg_t structure.
23
24       The following examples illustrates the transition:
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26          int i, count = 0;
27          uint64_t *codes;
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29          ret = pfm_get_event_encoding("RETIRED_INSTRUCTIONS", PFM_PLM3, NULL, &codes, &count);
30          if (ret != PFM_SUCCESS)
31             err(1", cannot get encoding %s", pfm_strerror(ret));
32
33          for(i=0; i < count; i++)
34             printf("count[%d]=0x%"PRIx64"\n", i, codes[i]);
35
36       is equivalent to:
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38          pfm_pmu_encode_arg_t arg;
39          int i;
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41          memset(&arg, 0, sizeof(arg));
42          arg.size = sizeof(arg);
43
44          ret = pfm_get_os_event_encoding("RETIRED_INSTRUCTIONS", PFM_PLM3, PFM_OS_NONE, &arg);
45          if (ret != PFM_SUCCESS)
46             err(1", cannot get encoding %s", pfm_strerror(ret));
47
48          for(i=0; i < arg.count; i++)
49             printf("count[%d]=0x%"PRIx64"\n", i, arg.codes[i]);
50
51          free(arg.codes);
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53       The encoding may take several 64-bit integers. The function can use the array passed in code if the number
54       of entries passed in count is big enough. However, if both *codes is NULL and count
55       is 0, the function allocates the memory necessary to store the encoding. It is up to the caller to
56       eventually free the memory. The number of 64-bit entries in codes is reflected in *count upon
57       return regardless of whether the codes was allocated or used as is. If the number of 64-bit integers is
58       greater than one, then the order in which each component is returned is PMU-model specific. Refer to the PMU
59       specific man page.
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61       The raw encoding means the encoding as mandated by the underlying PMU model. It may not be directly suitable
62       to pass to a kernel API. You may want to use API-specific library calls to ensure the correct encoding is passed.
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64       If fstr is not NULL, it will point to the fully qualified event string upon successful return. The string
65       contains the event name, any umask set, and the value of all the modifiers. It reflects what the encoding will
66       actually measure. The function allocates the memory to store the string. The caller must eventually free the
67       string.
68
69       Here is a example of how this function could be used:
70       #include <inttypes.h>
71       #include <err.h>
72       #include <perfmon/pfmlib.h>
73       int main(int argc, char **argv)
74       {
75          uint64_t *codes 0;
76          int count = 0;
77          int ret;
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79          ret = pfm_initialize();
80          if (ret != PFMLIB_SUCCESS)
81             err(1", cannot initialize library %s", pfm_strerror(ret));
82
83          ret = pfm_get_event_encoding("RETIRED_INSTRUCTIONS", PFM_PLM3, NULL, &codes, &count);
84          if (ret != PFM_SUCCESS)
85             err(1", cannot get encoding %s", pfm_strerror(ret));
86
87          for(i=0; i < count; i++)
88             printf("count[%d]=0x%"PRIx64"\n", i, codes[i]);
89
90          free(codes);
91          return 0;
92       }
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RETURN

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

100       PFM_ERR_TOOSMALL
101              The code argument is too small for the encoding.
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103       PFM_ERR_INVAL
104              The code or count argument is NULL.
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106       PFM_ERR_NOMEM
107              Not enough memory.
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109       PFM_ERR_NOTFOUND
110              Event not found.
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112       PFM_ERR_ATTR
113              Invalid event attribute (unit mask or modifier)
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115       PFM_ERR_ATTR_VAL
116              Invalid modifier value.
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118       PFM_ERR_ATTR_SET
119              attribute already set, cannot be changed.
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121       PFM_ERR_ATTR_UMASK
122              Missing unit mask.
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124       PFM_ERR_ATTR_FEATCOMB
125              Unit masks or features cannot be combined into a single event.
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AUTHOR

128       Stephane Eranian <eranian@gmail.com>
129

NAME

SYNOPSIS

DESCRIPTION

RETURN

ERRORS

AUTHOR

SEE ALSO