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diff --git a/tools/perf/Documentation/perf-daemon.txt b/tools/perf/Documentation/perf-daemon.txt new file mode 100644 index 000000000000..f558f8e4bc9b --- /dev/null +++ b/tools/perf/Documentation/perf-daemon.txt @@ -0,0 +1,208 @@ +perf-daemon(1) +============== + + +NAME +---- +perf-daemon - Run record sessions on background + + +SYNOPSIS +-------- +[verse] +'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 +-------- +linkperf:perf-record[1], linkperf:perf-config[1] |