1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH perfmonctl 2 2025-06-28 "Linux man-pages (unreleased)"
.SH NAME
perfmonctl \- interface to IA-64 performance monitoring unit
.SH SYNOPSIS
.nf
.B #include <syscall.h>
.B #include <perfmon.h>
.P
.BR "long perfmonctl(" "int narg;"
.BI " int " fd ", int " cmd ", void " arg [ narg "], int " narg );
.fi
.P
.IR Note :
There is no glibc wrapper for this system call; see HISTORY.
.SH DESCRIPTION
The IA-64-specific
.BR perfmonctl ()
system call provides an interface to the
PMU (performance monitoring unit).
The PMU consists of PMD (performance monitoring data) registers and
PMC (performance monitoring control) registers,
which gather hardware statistics.
.P
.BR perfmonctl ()
applies the operation
.I cmd
to the input arguments specified by
.IR arg .
The number of arguments is defined by
.IR narg .
The
.I fd
argument specifies the perfmon context to operate on.
.P
Supported values for
.I cmd
are:
.TP
.B PFM_CREATE_CONTEXT
.nf
.BI "perfmonctl(int " fd ", PFM_CREATE_CONTEXT, pfarg_context_t *" ctxt ", 1);"
.fi
Set up a context.
.IP
The
.I fd
parameter is ignored.
A new perfmon context is created as specified in
.I ctxt
and its file descriptor is returned in
.IR ctxt\->ctx_fd .
.IP
The file descriptor can be used in subsequent calls to
.BR perfmonctl ()
and can be used to read event notifications (type
.IR pfm_msg_t )
using
.BR read (2).
The file descriptor is pollable using
.BR select (2),
.BR poll (2),
and
.BR epoll (7).
.IP
The context can be destroyed by calling
.BR close (2)
on the file descriptor.
.TP
.B PFM_WRITE_PMCS
.\" pfm_write_pmcs()
.nf
.BI "perfmonctl(int " fd ", PFM_WRITE_PMCS, pfarg_reg_t *" pmcs ", n);"
.fi
Set PMC registers.
.TP
.B PFM_WRITE_PMDS
.nf
.BI "perfmonctl(int " fd ", PFM_WRITE_PMDS, pfarg_reg_t *" pmds ", n);"
.fi
.\" pfm_write_pmds()
Set PMD registers.
.TP
.B PFM_READ_PMDS
.\" pfm_read_pmds()
.nf
.BI "perfmonctl(int " fd ", PFM_READ_PMDS, pfarg_reg_t *" pmds ", n);"
.fi
Read PMD registers.
.TP
.B PFM_START
.\" pfm_start()
.nf
.\" .BI "perfmonctl(int " fd ", PFM_START, arg, 1);
.BI "perfmonctl(int " fd ", PFM_START, NULL, 0);"
.fi
Start monitoring.
.TP
.B PFM_STOP
.\" pfm_stop()
.nf
.BI "perfmonctl(int " fd ", PFM_STOP, NULL, 0);"
.fi
Stop monitoring.
.TP
.B PFM_LOAD_CONTEXT
.\" pfm_context_load()
.nf
.BI "perfmonctl(int " fd ", PFM_LOAD_CONTEXT, pfarg_load_t *" largs ", 1);"
.fi
Attach the context to a thread.
.TP
.B PFM_UNLOAD_CONTEXT
.\" pfm_context_unload()
.nf
.BI "perfmonctl(int " fd ", PFM_UNLOAD_CONTEXT, NULL, 0);"
.fi
Detach the context from a thread.
.TP
.B PFM_RESTART
.\" pfm_restart()
.nf
.BI "perfmonctl(int " fd ", PFM_RESTART, NULL, 0);"
.fi
Restart monitoring after receiving an overflow notification.
.TP
.B PFM_GET_FEATURES
.\" pfm_get_features()
.nf
.BI "perfmonctl(int " fd ", PFM_GET_FEATURES, pfarg_features_t *" arg ", 1);"
.fi
.TP
.B PFM_DEBUG
.\" pfm_debug()
.nf
.BI "perfmonctl(int " fd ", PFM_DEBUG, " val ", 0);"
.fi
If
.I val
is nonzero, enable debugging mode, otherwise disable.
.TP
.B PFM_GET_PMC_RESET_VAL
.\" pfm_get_pmc_reset()
.nf
.BI "perfmonctl(int " fd ", PFM_GET_PMC_RESET_VAL, pfarg_reg_t *" req ", n);"
.fi
Reset PMC registers to default values.
.\"
.\"
.\" .TP
.\" .B PFM_CREATE_EVTSETS
.\"
.\" create or modify event sets
.\" .nf
.\" .BI "perfmonctl(int " fd ", PFM_CREATE_EVTSETS, pfarg_setdesc_t *desc , n);
.\" .fi
.\" .TP
.\" .B PFM_DELETE_EVTSETS
.\" delete event sets
.\" .nf
.\" .BI "perfmonctl(int " fd ", PFM_DELETE_EVTSET, pfarg_setdesc_t *desc , n);
.\" .fi
.\" .TP
.\" .B PFM_GETINFO_EVTSETS
.\" get information about event sets
.\" .nf
.\" .BI "perfmonctl(int " fd ", PFM_GETINFO_EVTSETS, pfarg_setinfo_t *info, n);
.\" .fi
.SH RETURN VALUE
.BR perfmonctl ()
returns zero when the operation is successful.
On error, \-1 is returned and
.I errno
is set to indicate the error.
.SH STANDARDS
Linux on IA-64.
.SH HISTORY
Added in Linux 2.4;
.\" commit ecf5b72d5f66af843f189dfe9ce31598c3e48ad7
removed in Linux 5.10.
.P
This system call was broken for many years,
and ultimately removed in Linux 5.10.
.P
glibc does not provide a wrapper for this system call;
on kernels where it exists, call it using
.BR syscall (2).
.SH SEE ALSO
.BR gprof (1)
.P
The perfmon2 interface specification
|
