xref: /netbsd-src/usr.sbin/tprof/tprof.8 (revision 82d56013d7b633d116a93943de88e08335357a7c)
1.\"	$NetBSD: tprof.8,v 1.15 2019/10/11 20:18:20 jmcneill Exp $
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3.\" Copyright (c)2011 YAMAMOTO Takashi,
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27.Dd October 11, 2019
28.Dt TPROF 8
29.Os
30.Sh NAME
31.Nm tprof
32.Nd record tprof profiling samples
33.Sh SYNOPSIS
34.Nm
35.Ar op
36.Op Ar arguments
37.Sh DESCRIPTION
38The
39.Nm
40tool can be used to monitor hardware events (PMCs) during the execution of
41certain commands.
42.Pp
43The
44.Nm
45utility makes the kernel driver start profiling,
46executes the specified command,
47keeps recording samples from the kernel driver until the command finishes,
48and reports statistics to the standard error.
49.Pp
50The
51.Nm tprof
52pseudo driver and a suitable backend should be loaded beforehand.
53.Pp
54The
55.Nm
56utility accepts the following options.
57The first argument,
58.Ar op ,
59specifies the action to take.
60Valid actions are:
61.Bl -tag -width offline -offset indent
62.It list
63Display a list of performance counter events available on the system.
64.It monitor Xo
65.Fl e
66.Ar name:option
67.Op Fl o Ar outfile
68.Ar command
69.Xc
70Monitor the execution of command
71.Ar command .
72.Ar name
73specifies the name of the event to count; it must be taken from the list of
74available events.
75.Ar option
76specifies the source of the event; it must be a combination of
77.Ar u
78(userland) and
79.Ar k
80(kernel).
81The collected samples are written into the file
82.Ar outfile
83if specified.
84The default is
85.Dq Pa tprof.out .
86.It analyze Xo
87.Op Fl CkLPs
88.Op Fl p Ar pid
89.Ar file
90.Xc
91Analyze the samples produced by a previous run of
92.Nm tprof ,
93stored in
94.Ar file ,
95and generate a plain text representation of them.
96.Bl -tag -width XPXpidXX -offset indent
97.It Fl C
98Don't distinguish CPUs.
99All samples are treated as its CPU number is 0.
100.It Fl k
101Kernel only.
102Ignore samples for userland code.
103.It Fl L
104Don't distinguish LWPs.
105All samples are treated as its LWP ID is 0.
106.It Fl P
107Don't distinguish processes.
108All samples are treated as its PID is 0.
109.It Fl p Ar pid
110Process only samples for the process with PID
111.Ar pid
112and ignore the rest.
113.It Fl s
114Per symbol.
115.El
116.El
117.Sh EXAMPLES
118The following command profiles the system during 20 seconds and writes the
119samples into the file myfile.out.
120.Dl # tprof monitor -e llc-misses:k -o myfile.out sleep 20
121The following command displays the results of the sampling.
122.Dl # tprof analyze myfile.out
123.Sh SUPPORT
124The following CPU models are supported:
125.Bl -hyphen -compact -offset indent
126.It
127ARMv7
128.It
129ARMv8
130.It
131x86 AMD Family 10h
132.It
133x86 AMD Family 15h
134.It
135x86 AMD Family 17h
136.It
137x86 Intel Generic (all Intel CPUs)
138.It
139x86 Intel Skylake/Kabylake
140.It
141x86 Intel Silvermont/Airmont
142.It
143x86 Intel Goldmont
144.It
145x86 Intel Goldmont Plus
146.El
147.Sh DIAGNOSTICS
148The
149.Nm
150utility reports the following statistics about the activities of the
151.Nm tprof
152pseudo driver.
153.Bl -tag -width dropbuf_samples
154.It sample
155The number of samples collected and prepared for userland consumption.
156.It overflow
157The number of samples dropped because the per-CPU buffer was full.
158.It buf
159The number of buffers successfully prepared for userland consumption.
160.It emptybuf
161The number of buffers which have been dropped because they were empty.
162.It dropbuf
163The number of buffers dropped because the number of buffers kept in the kernel
164exceeds the limit.
165.It dropbuf_samples
166The number of samples dropped because the buffers containing the samples
167were dropped.
168.El
169.Sh SEE ALSO
170.Xr tprof 4
171.Sh AUTHORS
172.An -nosplit
173The
174.Nm
175utility was written by
176.An YAMAMOTO Takashi .
177It was revamped by
178.An Maxime Villard
179in 2018.
180.Sh CAVEATS
181The contents and representation of recorded samples are undocumented and
182will likely be changed for future releases of
183.Nx
184in an incompatible way.
185