cpc_event(3cpc)

1cpc_event(3CPC)   CPU Performance Counters Library Functions   cpc_event(3CPC)
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NAME

6       cpc_event - data structure to describe CPU performance counters
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SYNOPSIS

9       #include <libcpc.h>
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DESCRIPTION

13       The  libcpc  interfaces  manipulate  CPU performance counters using the
14       cpc_event_t data structure. This structure contains several fields that
15       are  common  to  all processors, and some that are processor-dependent.
16       These structures can be declared by a consumer of  the  API,  thus  the
17       size  and offsets of the fields and the entire data structure are fixed
18       per processor for any particular version of the library. See   cpc_ver‐
19       sion(3CPC) for details of library versioning.
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21   SPARC
22       For UltraSPARC, the structure contains the following members:
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24         typedef struct {
25                 int ce_cpuver;
26                 hrtime_t ce_hrt;
27                 uint64_t ce_tick;
28                 uint64_t ce_pic[2];
29                 uint64_t ce_pcr;
30         } cpc_event_t;
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33   x86
34       For Pentium, the structure contains the following members:
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36         typedef struct {
37                 int ce_cpuver;
38                 hrtime_t ce_hrt;
39                 uint64_t ce_tsc;
40                 uint64_t ce_pic[2];
41                 uint32_t ce_pes[2];
42         #define ce_cesr ce_pes[0]
43         } cpc_event_t;
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47       The  APIs are used to manipulate the highly processor-dependent control
48       registers (the ce_pcr, ce_cesr, and ce_pes fields); the  programmer  is
49       strongly  advised  not  to  reference those fields directly in portable
50       code. The ce_pic array elements contain 64-bit accumulated counter val‐
51       ues.   The hardware registers are virtualized to 64-bit quantities even
52       though the underlying hardware only supports  32-bits  (UltraSPARC)  or
53       40-bits (Pentium) before overflow.
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56       The   ce_hrt field is a high resolution timestamp taken at the time the
57       counters were sampled by the kernel.  This uses the  same  timebase  as
58       gethrtime(3C).
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61       On SPARC V9 machines, the number of cycles spent running on the proces‐
62       sor is computed from samples of the processor-dependent   %tick  regis‐
63       ter,  and placed in the  ce_tick field. On Pentium processors, the pro‐
64       cessor-dependent time-stamp counter register is similarly  sampled  and
65       placed in the ce_tsc field.
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ATTRIBUTES

68       See attributes(5) for descriptions of the following attributes:
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73       ┌─────────────────────────────┬─────────────────────────────┐
74       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
75       ├─────────────────────────────┼─────────────────────────────┤
76       │Interface Stability          │Evolving                     │
77       └─────────────────────────────┴─────────────────────────────┘
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NAME

SYNOPSIS

DESCRIPTION

ATTRIBUTES

SEE ALSO