xref: /freebsd/lib/libpmc/pmc_set.3 (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1.\" Copyright (c) 2007 Joseph Koshy.  All rights reserved.
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24.\" $FreeBSD$
25.\"
26.Dd November 25, 2007
27.Dt PMC_SET 3
28.Os
29.Sh NAME
30.Nm pmc_set
31.Nd set the reload count of a sampling PMC
32.Sh LIBRARY
33.Lb libpmc
34.Sh SYNOPSIS
35.In pmc.h
36.Ft int
37.Fn pmc_set "pmc_id_t pmc" "pmc_value_t value"
38.Sh DESCRIPTION
39Function
40.Fn pmc_set
41is used to set the reload value of sampling PMCs.
42Argument
43.Fa pmc
44specified the handle a previously allocate sampling mode PMC.
45Argument
46.Fa value
47specifies the reload count.
48.Pp
49Sampling PMCs will interrupt the CPU after the number of
50hardware events specified by the reload count are seen.
51After the sampling interrupt is processed the underlying hardware will
52be reloaded with the specified count and the hardware
53automatically restarted by
54.Xr hwpmc 4 .
55.Pp
56Function
57.Fn pmc_set
58should be called on PMC in a quiescent state.
59.Sh RETURN VALUES
60.Rv -std pmc_set
61.Sh ERRORS
62A call to
63.Fn pmc_set
64may fail with the following errors:
65.Bl -tag -width Er
66.It Bq Er EINVAL
67The current process did not own a PMC with the specified handle.
68.It Bq Er EBUSY
69The specified PMC was already running.
70.El
71.Sh SEE ALSO
72.Xr pmc 3 ,
73.Xr hwpmc 4
74