1 .\" $NetBSD: profil.2,v 1.13 2003/08/07 16:44:04 agc Exp $
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33 .\" @(#)profil.2 8.1 (Berkeley) 6/4/93
40 .Nd control process profiling
46 .Fn profil "char *samples" "size_t size" "u_long offset" "u_int scale"
50 function enables or disables
51 program counter profiling of the current process.
52 If profiling is enabled,
53 then at every clock tick,
54 the kernel updates an appropriate count in the
62 bytes and is divided into
63 a series of 16-bit bins.
64 Each bin counts the number of times the program counter
65 was in a particular address range in the process
66 when a clock tick occurred while profiling was enabled.
67 For a given program counter address,
68 the number of the corresponding bin is given
70 .Bd -literal -offset indent
71 [(pc - offset) / 2] * scale / 65536
76 parameter is the lowest address at which
77 the kernel takes program counter samples.
80 parameter ranges from 1 to 65536 and
81 can be used to change the span of the bins.
82 A scale of 65536 maps each bin to 2 bytes of address range;
83 a scale of 32768 gives 4 bytes, 16384 gives 8 bytes and so on.
84 Intermediate values provide approximate intermediate ranges.
87 value of 0 disables profiling.
91 value is nonzero and the buffer
93 contains an illegal address,
96 profiling is terminated and
103 .Bl -tag -width /usr/lib/gcrt0.o -compact
104 .It Pa /usr/lib/gcrt0.o
105 profiling C run-time startup file
107 conventional name for profiling output file.
108 This may be different if the PROFDIR environment variable is set.
111 The following error may be reported:
116 contains an invalid address.
122 .\" wish I knew... probably v7.
124 This routine should be named
129 argument should really be a vector of type
130 .Fa "unsigned short" .
132 The format of the gmon.out file is undocumented.