perf-daemon(1)

1PERF-DAEMON(1)                    perf Manual                   PERF-DAEMON(1)
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NAME

6       perf-daemon - Run record sessions on background
7

SYNOPSIS

9       perf daemon
10       perf daemon [<options>]
11       perf daemon start  [<options>]
12       perf daemon stop   [<options>]
13       perf daemon signal [<options>]
14       perf daemon ping   [<options>]
15

DESCRIPTION

17       This command allows to run simple daemon process that starts and
18       monitors configured record sessions.
19
20       You can imagine perf daemon of background process with several perf
21       record child tasks, like:
22
23           # ps axjf
24           ...
25                1  916507 ... perf daemon start
26           916507  916508 ...  \_ perf record --control=fifo:control,ack -m 10M -e cycles --overwrite --switch-output -a
27           916507  916509 ...  \_ perf record --control=fifo:control,ack -m 20M -e sched:* --overwrite --switch-output -a
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29       Not every perf record session is suitable for running under daemon.
30       User need perf session that either produces data on query, like the
31       flight recorder sessions in above example or session that is configured
32       to produce data periodically, like with --switch-output configuration
33       for time and size.
34
35       Each session is started with control setup (with perf record --control
36       options).
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38       Sessions are configured through config file, see CONFIG FILE section
39       with EXAMPLES.
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OPTIONS

42       -v, --verbose
43           Be more verbose.
44
45       --config=<PATH>
46           Config file path. If not provided, perf will check system and
47           default locations (/etc/perfconfig, $HOME/.perfconfig).
48
49       --base=<PATH>
50           Base directory path. Each daemon instance is running on top of base
51           directory. Only one instance of server can run on top of one
52           directory at the time.
53
54       All generic options are available also under commands.
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START COMMAND

57       The start command creates the daemon process.
58
59       -f, --foreground
60           Do not put the process in background.
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STOP COMMAND

63       The stop command stops all the session and the daemon process.
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SIGNAL COMMAND

66       The signal command sends signal to configured sessions.
67
68       --session
69           Send signal to specific session.
70

PING COMMAND

72       The ping command sends control ping to configured sessions.
73
74       --session
75           Send ping to specific session.
76

CONFIG FILE

78       The daemon is configured within standard perf config file by following
79       new variables:
80
81       daemon.base: Base path for daemon data. All sessions data are stored
82       under this path.
83
84       session-<NAME>.run: Defines new record session. The value is record’s
85       command line without the record keyword.
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87       Each perf record session is run in daemon.base/<NAME> directory.
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EXAMPLES

90       Example with 2 record sessions:
91
92           # cat ~/.perfconfig
93           [daemon]
94           base=/opt/perfdata
95
96           [session-cycles]
97           run = -m 10M -e cycles --overwrite --switch-output -a
98
99           [session-sched]
100           run = -m 20M -e sched:* --overwrite --switch-output -a
101
102       Starting the daemon:
103
104           # perf daemon start
105
106       Check sessions:
107
108           # perf daemon
109           [603349:daemon] base: /opt/perfdata
110           [603350:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a
111           [603351:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
112
113       First line is daemon process info with configured daemon base.
114
115       Check sessions with more info:
116
117           # perf daemon -v
118           [603349:daemon] base: /opt/perfdata
119             output:  /opt/perfdata/output
120             lock:    /opt/perfdata/lock
121             up:      1 minutes
122           [603350:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a
123             base:    /opt/perfdata/session-cycles
124             output:  /opt/perfdata/session-cycles/output
125             control: /opt/perfdata/session-cycles/control
126             ack:     /opt/perfdata/session-cycles/ack
127             up:      1 minutes
128           [603351:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
129             base:    /opt/perfdata/session-sched
130             output:  /opt/perfdata/session-sched/output
131             control: /opt/perfdata/session-sched/control
132             ack:     /opt/perfdata/session-sched/ack
133             up:      1 minutes
134
135       The base path is daemon/session base. The lock file is daemon’s lock
136       file guarding that no other daemon is running on top of the base. The
137       output file is perf record output for specific session. The control and
138       ack files are perf control files. The up number shows minutes
139       daemon/session is running.
140
141       Make sure control session is online:
142
143           # perf daemon ping
144           OK   cycles
145           OK   sched
146
147       Send USR2 signal to session cycles to generate perf.data file:
148
149           # perf daemon signal --session cycles
150           signal 12 sent to session 'cycles [603452]'
151
152           # tail -2  /opt/perfdata/session-cycles/output
153           [ perf record: dump data: Woken up 1 times ]
154           [ perf record: Dump perf.data.2020123017013149 ]
155
156       Send USR2 signal to all sessions:
157
158           # perf daemon signal
159           signal 12 sent to session 'cycles [603452]'
160           signal 12 sent to session 'sched [603453]'
161
162           # tail -2  /opt/perfdata/session-cycles/output
163           [ perf record: dump data: Woken up 1 times ]
164           [ perf record: Dump perf.data.2020123017024689 ]
165           # tail -2  /opt/perfdata/session-sched/output
166           [ perf record: dump data: Woken up 1 times ]
167           [ perf record: Dump perf.data.2020123017024713 ]
168
169       Stop daemon:
170
171           # perf daemon stop
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