commit217f0b1e99upstream. When using rtla timerlat with userspace threads (-u or -U), rtla disables the OSNOISE_WORKLOAD option in /sys/kernel/tracing/osnoise/options. This option is not re-enabled in a subsequent run with kernel-space threads, leading to rtla collecting no results if the previous run exited abnormally: $ rtla timerlat top -u ^\Quit (core dumped) $ rtla timerlat top -k -d 1s Timer Latency 0 00:00:01 | IRQ Timer Latency (us) | Thread Timer Latency (us) CPU COUNT | cur min avg max | cur min avg max The issue persists until OSNOISE_WORKLOAD is set manually by running: $ echo OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options Set OSNOISE_WORKLOAD when running rtla with kernel-space threads if available to fix the issue. Cc: stable@vger.kernel.org Cc: John Kacur <jkacur@redhat.com> Cc: Luis Goncalves <lgoncalv@redhat.com> Link: https://lore.kernel.org/20250107144823.239782-4-tglozar@redhat.com Fixes:cdca4f4e5e("rtla/timerlat_top: Add timerlat user-space support") Signed-off-by: Tomas Glozar <tglozar@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> [ params->kernel_workload does not exist in 6.6, use !params->user_top ] Signed-off-by: Tomas Glozar <tglozar@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
RTLA: Real-Time Linux Analysis tools The rtla meta-tool includes a set of commands that aims to analyze the real-time properties of Linux. Instead of testing Linux as a black box, rtla leverages kernel tracing capabilities to provide precise information about the properties and root causes of unexpected results. Installing RTLA RTLA depends on the following libraries and tools: - libtracefs - libtraceevent It also depends on python3-docutils to compile man pages. For development, we suggest the following steps for compiling rtla: $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git $ cd libtraceevent/ $ make $ sudo make install $ cd .. $ git clone git://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git $ cd libtracefs/ $ make $ sudo make install $ cd .. $ cd $rtla_src $ make $ sudo make install For further information, please refer to the rtla man page.