xref: /freebsd/lib/libpmc/pmc_set.3 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
1.\" Copyright (c) 2007 Joseph Koshy.  All rights reserved.
2.\"
3.\" Redistribution and use in source and binary forms, with or without
4.\" modification, are permitted provided that the following conditions
5.\" are met:
6.\" 1. Redistributions of source code must retain the above copyright
7.\"    notice, this list of conditions and the following disclaimer.
8.\" 2. Redistributions in binary form must reproduce the above copyright
9.\"    notice, this list of conditions and the following disclaimer in the
10.\"    documentation and/or other materials provided with the distribution.
11.\"
12.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
13.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
14.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
15.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
16.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
17.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
18.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
19.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
20.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
21.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
22.\" SUCH DAMAGE.
23.\"
24.Dd November 25, 2007
25.Dt PMC_SET 3
26.Os
27.Sh NAME
28.Nm pmc_set
29.Nd set the reload count of a sampling PMC
30.Sh LIBRARY
31.Lb libpmc
32.Sh SYNOPSIS
33.In pmc.h
34.Ft int
35.Fn pmc_set "pmc_id_t pmc" "pmc_value_t value"
36.Sh DESCRIPTION
37Function
38.Fn pmc_set
39is used to set the reload value of sampling PMCs.
40Argument
41.Fa pmc
42specified the handle a previously allocate sampling mode PMC.
43Argument
44.Fa value
45specifies the reload count.
46.Pp
47Sampling PMCs will interrupt the CPU after the number of
48hardware events specified by the reload count are seen.
49After the sampling interrupt is processed the underlying hardware will
50be reloaded with the specified count and the hardware
51automatically restarted by
52.Xr hwpmc 4 .
53.Pp
54Function
55.Fn pmc_set
56should be called on PMC in a quiescent state.
57.Sh RETURN VALUES
58.Rv -std pmc_set
59.Sh ERRORS
60A call to
61.Fn pmc_set
62may fail with the following errors:
63.Bl -tag -width Er
64.It Bq Er EINVAL
65The current process did not own a PMC with the specified handle.
66.It Bq Er EBUSY
67The specified PMC was already running.
68.El
69.Sh SEE ALSO
70.Xr pmc 3 ,
71.Xr hwpmc 4
72