xref: /freebsd/lib/libpmc/pmc.tsc.3 (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
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24.\" $FreeBSD$
25.\"
26.Dd October 4, 2008
27.Dt PMC.TSC 3
28.Os
29.Sh NAME
30.Nm pmc.tsc
31.Nd measurements using the i386 timestamp counter
32.Sh LIBRARY
33.Lb libpmc
34.Sh SYNOPSIS
35.In pmc.h
36.Sh DESCRIPTION
37In the i386 architecture, the timestamp counter is a monotonically
38non-decreasing counter that counts processor cycles.
39.Pp
40This counter may be selected specifying an event specifier
41.Dq Li tsc
42to
43.Xr pmc_allocate 3 .
44The TSC is a read-only counter that may only be allocated in
45system-wide counting mode.
46The
47.Dq Li tsc
48event does not support further event qualifiers.
49.Pp
50Multiple processes are allowed to allocate the TSC.
51Once allocated, the TSC may be read using the
52.Fn pmc_read
53function, or by using the
54.Li RDTSC
55instruction.
56.Ss Event Name Aliases
57The alias
58.Dq Li cycles
59maps to the TSC.
60.Sh SEE ALSO
61.Xr pmc 3 ,
62.Xr pmc.atom 3 ,
63.Xr pmc.core 3 ,
64.Xr pmc.core2 3 ,
65.Xr pmc.iaf 3 ,
66.Xr pmc.k7 3 ,
67.Xr pmc.k8 3 ,
68.Xr pmc.soft 3 ,
69.Xr pmclog 3 ,
70.Xr hwpmc 4
71.Sh HISTORY
72The
73.Nm pmc
74library first appeared in
75.Fx 6.0 .
76.Sh AUTHORS
77The
78.Lb libpmc
79library was written by
80.An Joseph Koshy Aq Mt jkoshy@FreeBSD.org .
81