NAME

       perf-daemon - Run record sessions on background

SYNOPSIS

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

DESCRIPTION

       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

       -v, --verbose
           Be more verbose.

       --config=<PATH>
           Config file path. If not provided, perf will check system and default locations
           (/etc/perfconfig, $HOME/.perfconfig).

       --base=<PATH>
           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

       The start command creates the daemon process.

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

STOP COMMAND

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

SIGNAL COMMAND

       The signal command sends signal to configured sessions.

       --session
           Send signal to specific session.

PING COMMAND

       The ping command sends control ping to configured sessions.

       --session
           Send ping to specific session.

CONFIG FILE

       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

       Example with 2 record sessions:

           # cat ~/.perfconfig
           [daemon]
           base=/opt/perfdata

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

           [session-sched]
           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 perf.data 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 perf.data.2020123017013149 ]

       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 perf.data.2020123017024689 ]
           # tail -2  /opt/perfdata/session-sched/output
           [ perf record: dump data: Woken up 1 times ]
           [ perf record: Dump perf.data.2020123017024713 ]

       Stop daemon:

           # perf daemon stop

SEE ALSO

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