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-rw-r--r--tools/perf/Documentation/perf-daemon.txt30
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diff --git a/tools/perf/Documentation/perf-daemon.txt b/tools/perf/Documentation/perf-daemon.txt
index 1a4158cd973e..173b3f9f3a41 100644
--- a/tools/perf/Documentation/perf-daemon.txt
+++ b/tools/perf/Documentation/perf-daemon.txt
@@ -20,6 +20,20 @@ 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.
OPTIONS
-------
@@ -43,6 +57,22 @@ START COMMAND
The start command creates the daemon process.
+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.
+
+
SEE ALSO
--------
linkperf:perf-record[1], linkperf:perf-config[1]