lttng-enable-rotation.1.txt: --timer option should be fairly precise

[lttng-tools.git] / doc / man / lttng-enable-rotation.1.txt

diff --git a/doc/man/lttng-enable-rotation.1.txt b/doc/man/lttng-enable-rotation.1.txt
index 53189da925137ef2cb2c431a794b06d33036a531..e8970cd97b64187eac8b3ad8647bfd8d2073477c 100644 (file)
--- a/doc/man/lttng-enable-rotation.1.txt
+++ b/doc/man/lttng-enable-rotation.1.txt
@@ -10,8 +10,8 @@ lttng-enable-rotation - Set a tracing session's rotation schedule
 SYNOPSIS
 --------
 [verse]
-*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* (option:--timer='PERIOD' | option:--size='SIZE')
-      [option:--session='SESSION']
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-rotation* [option:--session='SESSION']
+      (option:--timer='PERIOD' | option:--size='SIZE' | option:--timer='PERIOD' option:--size='SIZE')
 
 
 DESCRIPTION
@@ -30,23 +30,27 @@ so that an automatic rotation occurs every time the total size of the
 flushed part of the current trace chunk is at least 'SIZE' (bytes
 without a unit suffix).
 
-With both the option:--timer and option:--size options, LTTng checks the
+For both option:--timer and option:--size options, LTTng checks the
 schedule condition periodically using the monitor timers of the tracing
-session's channels. This means that, with the option:--timer option, the
-automatic rotation can occur when the elapsed time since the last
-automatic rotation is greater than 'PERIOD', and with the option:--size
-option, the automatic rotation can occur when the size of the flushed
-part of the current trace chunk is greater than 'SIZE'. See the
-nloption:--monitor-timer option in man:lttng-enable-channel(1) for more
-information about the monitor timer.
+session's channels (see the nloption:--monitor-timer option of the
+man:lttng-enable-channel(1) command). This means that:
+
+* With the option:--timer option, the automatic rotation can occur when
+  the elapsed time since the last automatic rotation is slightly greater
+  than 'PERIOD'. The exact precision is governed by the monitor timer's
+  precision, which relies on the precision of the platform's
+  implementation of POSIX timers.
+
+* With the option:--size option, the automatic rotation can occur when
+  the size of the flushed part of the current trace chunk is greater
+  than 'SIZE'.
+
+You can combine the option:--timer and option:--size options.
 
 The naming convention of a trace chunk archive which an automatic
 rotation creates is the same as with the immediate rotation command,
 man:lttng-rotate(1).
 
-For a given tracing session, you cannot set multiple rotation schedules
-with the option:--timer or the option:--size option.
-
 You can unset a rotation schedule with the man:lttng-disable-rotation(1)
 command.
 
@@ -59,8 +63,6 @@ include::common-cmd-options-head.txt[]
 
 Rotation schedule condition
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
-One of:
-
 option:--size='SIZE'::
     Set a rotation schedule so that an automatic rotation occurs every
     time the total size of the flushed part of the current trace chunk