perf-daemon(1) — Linux manual page


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

NAME         top

       perf-daemon - Run record sessions on background

SYNOPSIS         top

       perf daemon
       perf daemon [<options>]
       perf daemon start  [<options>]
       perf daemon stop   [<options>]
       perf daemon signal [<options>]
       perf daemon ping   [<options>]

DESCRIPTION         top

       This command allows to run simple daemon process that starts and
       monitors configured record sessions.

       You can imagine perf daemon of background process with several
       perf record child tasks, like:

           # ps axjf
                1  916507 ... perf daemon start
           916507  916508 ...  \_ perf record --control=fifo:control,ack -m 10M -e cycles --overwrite --switch-output -a
           916507  916509 ...  \_ perf record --control=fifo:control,ack -m 20M -e sched:* --overwrite --switch-output -a

       Not every perf record session is suitable for running under
       daemon. User need perf session that either produces data on
       query, like the flight recorder sessions in above example or
       session that is configured to produce data periodically, like
       with --switch-output configuration for time and size.

       Each session is started with control setup (with perf record
       --control options).

       Sessions are configured through config file, see CONFIG FILE
       section with EXAMPLES.

OPTIONS         top

       -v, --verbose
           Be more verbose.

           Config file path. If not provided, perf will check system and
           default locations (/etc/perfconfig, $HOME/.perfconfig).

           Base directory path. Each daemon instance is running on top
           of base directory. Only one instance of server can run on top
           of one directory at the time.

       All generic options are available also under commands.

START COMMAND         top

       The start command creates the daemon process.

       -f, --foreground
           Do not put the process in background.

STOP COMMAND         top

       The stop command stops all the session and the daemon process.

SIGNAL COMMAND         top

       The signal command sends signal to configured sessions.

           Send signal to specific session.

PING COMMAND         top

       The ping command sends control ping to configured sessions.

           Send ping to specific session.

CONFIG FILE         top

       The daemon is configured within standard perf config file by
       following new variables:

       daemon.base: Base path for daemon data. All sessions data are
       stored under this path.

       session-<NAME>.run: Defines new record session. The value is
       record’s command line without the record keyword.

       Each perf record session is run in daemon.base/<NAME> directory.

EXAMPLES         top

       Example with 2 record sessions:

           # cat ~/.perfconfig

           run = -m 10M -e cycles --overwrite --switch-output -a

           run = -m 20M -e sched:* --overwrite --switch-output -a

       Starting the daemon:

           # perf daemon start

       Check sessions:

           # perf daemon
           [603349:daemon] base: /opt/perfdata
           [603350:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a
           [603351:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a

       First line is daemon process info with configured daemon base.

       Check sessions with more info:

           # perf daemon -v
           [603349:daemon] base: /opt/perfdata
             output:  /opt/perfdata/output
             lock:    /opt/perfdata/lock
             up:      1 minutes
           [603350:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a
             base:    /opt/perfdata/session-cycles
             output:  /opt/perfdata/session-cycles/output
             control: /opt/perfdata/session-cycles/control
             ack:     /opt/perfdata/session-cycles/ack
             up:      1 minutes
           [603351:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
             base:    /opt/perfdata/session-sched
             output:  /opt/perfdata/session-sched/output
             control: /opt/perfdata/session-sched/control
             ack:     /opt/perfdata/session-sched/ack
             up:      1 minutes

       The base path is daemon/session base. The lock file is daemon’s
       lock file guarding that no other daemon is running on top of the
       base. The output file is perf record output for specific session.
       The control and ack files are perf control files. The up number
       shows minutes daemon/session is running.

       Make sure control session is online:

           # perf daemon ping
           OK   cycles
           OK   sched

       Send USR2 signal to session cycles to generate file:

           # perf daemon signal --session cycles
           signal 12 sent to session 'cycles [603452]'

           # tail -2  /opt/perfdata/session-cycles/output
           [ perf record: dump data: Woken up 1 times ]
           [ perf record: Dump ]

       Send USR2 signal to all sessions:

           # perf daemon signal
           signal 12 sent to session 'cycles [603452]'
           signal 12 sent to session 'sched [603453]'

           # tail -2  /opt/perfdata/session-cycles/output
           [ perf record: dump data: Woken up 1 times ]
           [ perf record: Dump ]
           # tail -2  /opt/perfdata/session-sched/output
           [ perf record: dump data: Woken up 1 times ]
           [ perf record: Dump ]

       Stop daemon:

           # perf daemon stop

SEE ALSO         top

       perf-record(1), perf-config(1)

COLOPHON         top

       This page is part of the perf (Performance analysis tools for
       Linux (in Linux source tree)) project.  Information about the
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perf                           2021-02-11                 PERF-DAEMON(1)