Commit 82374995 authored by Tomas Glozar's avatar Tomas Glozar
Browse files

Documentation/rtla: Document SIGINT behavior 



The behavior of RTLA on receiving SIGINT is currently undocumented.

Describe it in RTLA's common appendix that appears in man pages for all
RTLA tools to avoid confusion.

Suggested-by: default avatarAttila Fazekas <afazekas@redhat.com>
Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20260324123229.152424-1-tglozar@redhat.com


Signed-off-by: default avatarTomas Glozar <tglozar@redhat.com>
parent be8058f3

Documentation/tools/rtla/common_appendix.txt

+21 −0
Original line number Diff line number Diff line 
.. SPDX-License-Identifier: GPL-2.0



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

===========