.. SPDX-License-Identifier: GPL-2.0

UNSETTING OPTIONS
=================

The effect of most command line options can be reverted by prepending "no-" to
the long variant of the option, for example:

$ rtla timerlat top -p 100 --no-period

resets the period back to the default value of 1000 us.

If a command line option sets multiple RTLA parameters at once, the inverted
option will revert all of them, even if they were not set by the particular
option. For example, since using "--auto" implies "--trace", specifying
"--trace --no-auto" will also disable trace output, just like if "--no-trace"
was specified.


SIGINT BEHAVIOR
===============

On the first SIGINT, RTLA exits after collecting all outstanding samples up to
the point of receiving the signal.

When receiving more than one SIGINT, RTLA discards any outstanding samples, and
exits while displaying only samples that have already been processed.

If SIGINT is received during RTLA cleanup, RTLA exits immediately via
the default signal handler.

Note: For the purpose of SIGINT behavior, the expiry of duration specified via
the -d/--duration option is treated as equivalent to receiving a SIGINT. For
example, a SIGINT received after duration expired but samples have not been
processed yet will drop any outstanding samples.

Also note that when using the timerlat tool in BPF mode, samples are processed
in-kernel; RTLA only copies them out to display them to the user. A second
SIGINT does not affect in-kernel sample aggregation.

EXIT STATUS
===========

::

 0    Passed: the test did not hit the stop tracing condition
 1    Error: invalid argument
 2    Failed: the test hit the stop tracing condition
 129  Help: either user requested help or incorrect option was specified

REPORTING BUGS
==============
Report bugs to <linux-kernel@vger.kernel.org>
and <linux-trace-devel@vger.kernel.org>

LICENSE
=======
**rtla** is Free Software licensed under the GNU GPLv2

COPYING
=======
Copyright \(C) 2021 Red Hat, Inc. Free use of this software is granted under
the terms of the GNU Public License (GPL).