kernel/linux.git/tools/tracing/rtla/src/utils.h, branch v6.19.11

rtla: Fix -C/--cgroup interface

2025-11-21T09:30:27+00:00

Currently, user can only specify cgroup to the tracer's thread the following ways: `-C[cgroup]` `-C[=cgroup]` `--cgroup[=cgroup]` If user tries to specify cgroup as `-C [cgroup]` or `--cgroup [cgroup]`, the parser silently fails and rtla's cgroup is used for the tracer threads. To make interface more user-friendly, allow user to specify cgroup in the aforementioned way, i.e. `-C [cgroup]` and `--cgroup [cgroup]`. Refactor identical logic between -t/--trace and -C/--cgroup into a common function. Change documentation to reflect this user interface change. Fixes: a957cbc02531 ("rtla: Add -C cgroup support") Signed-off-by: Ivan Pravdin Reviewed-by: Tomas Glozar Link: https://lore.kernel.org/r/16132f1565cf5142b5fbd179975be370b529ced7.1762186418.git.ipravdin.official@gmail.com [ use capital letter in subject, as required by tracing subsystem ] Signed-off-by: Tomas Glozar

tools/rtla: Add fatal() and replace error handling pattern

2025-11-21T09:30:27+00:00

The code contains some technical debt in error handling, which complicates the consolidation of duplicated code. Introduce an fatal() function to replace the common pattern of err_msg() followed by exit(EXIT_FAILURE), reducing the length of an already long function. Further patches using fatal() follow. Signed-off-by: Costa Shulyupin Reviewed-by: Tomas Glozar Link: https://lore.kernel.org/r/20251011082738.173670-2-costa.shul@redhat.com Signed-off-by: Tomas Glozar

rtla: Set distinctive exit value for failed tests

2025-05-07T19:36:19+00:00

A test is considered failed when a sample trace exceeds the threshold. Failed tests return the same exit code as passed tests, requiring test frameworks to determine the result by searching for "hit stop tracing" in the output. Assign a distinct exit code for failed tests to enable the use of shell expressions and seamless integration with testing frameworks without the need to parse output. Add enum type for return value. Update `make check`. Cc: Daniel Bristot de Oliveira Cc: John Kacur Cc: "Luis Claudio R. Goncalves" Cc: Eder Zulian Cc: Dan Carpenter Cc: Jan Stancek Link: https://lore.kernel.org/20250417185757.2194541-1-costa.shul@redhat.com Signed-off-by: Costa Shulyupin Reviewed-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla/utils: Add idle state disabling via libcpupower

2024-10-17T21:13:15+00:00

Add functions to utils.c to disable idle states through functions of libcpupower. This will serve as the basis for disabling idle states per cpu when running timerlat. Link: https://lore.kernel.org/20241017140914.3200454-4-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

tools/rtla: fix collision with glibc sched_attr/sched_set_attr

2024-10-11T00:31:48+00:00

glibc commit 21571ca0d703 ("Linux: Add the sched_setattr and sched_getattr functions") now also provides 'struct sched_attr' and sched_setattr() which collide with the ones from rtla. In file included from src/trace.c:11: src/utils.h:49:8: error: redefinition of ‘struct sched_attr’ 49 | struct sched_attr { | ^~~~~~~~~~ In file included from /usr/include/bits/sched.h:60, from /usr/include/sched.h:43, from /usr/include/tracefs/tracefs.h:10, from src/trace.c:4: /usr/include/linux/sched/types.h:98:8: note: originally defined here 98 | struct sched_attr { | ^~~~~~~~~~ Define 'struct sched_attr' conditionally, similar to what strace did: https://lore.kernel.org/all/20240930222913.3981407-1-raj.khem@gmail.com/ and rename rtla's version of sched_setattr() to avoid collision. Link: https://lore.kernel.org/8088f66a7a57c1b209cd8ae0ae7c336a7f8c930d.1728572865.git.jstancek@redhat.com Signed-off-by: Jan Stancek Signed-off-by: Steven Rostedt (Google)

tools/rtla: Replace setting prio with nice for SCHED_OTHER

2024-02-12T09:56:36+00:00

Since the sched_priority for SCHED_OTHER is always 0, it makes no sence to set it. Setting nice for SCHED_OTHER seems more meaningful. Link: https://lkml.kernel.org/r/20240207065142.1753909-1-limingming3@lixiang.com Cc: stable@vger.kernel.org Fixes: b1696371d865 ("rtla: Helper functions for rtla") Signed-off-by: limingming3 Signed-off-by: Daniel Bristot de Oliveira

rtla/timerlat_top: Add timerlat user-space support

2023-06-13T20:38:51+00:00

Add the support for running timerlat threads in user-space. In this mode, enabled with -u/--user-threads, timerlat dispatches user-space processes that will loop in the timerlat_fd, measuring the overhead for going to user-space and then returning to the kernel - in addition to the existing measurements. Here is one example of the tool's output with -u enabled: $ sudo timerlat top -u -d 600 -q Timer Latency 0 00:10:01 | IRQ Timer Latency (us) | Thread Timer Latency (us) | Ret user Timer Latency (us) CPU COUNT | cur min avg max | cur min avg max | cur min avg max 0 #600001 | 0 0 0 3 | 2 1 2 9 | 3 2 3 15 1 #600001 | 0 0 0 2 | 2 1 2 13 | 2 2 3 18 2 #600001 | 0 0 0 10 | 2 1 2 16 | 3 2 3 20 3 #600001 | 0 0 0 7 | 2 1 2 10 | 3 2 3 11 4 #600000 | 0 0 0 16 | 2 1 2 41 | 3 2 3 58 5 #600000 | 0 0 0 3 | 2 1 2 10 | 3 2 3 13 6 #600000 | 0 0 0 5 | 2 1 2 7 | 3 2 3 10 7 #600000 | 0 0 0 1 | 2 1 2 7 | 3 2 3 10 The tuning setup like -p or -C work for the user-space threads as well. Link: https://lkml.kernel.org/r/758ad2292a0a1d884138d08219e1a0f572d257a2.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Automatically move rtla to a house-keeping cpu

2023-06-13T20:30:13+00:00

When the user sets -c try to move rtla out of the , even without an -H option. This is useful to avoid having rtla interfering with the workload. This works by removing from rtla's current affinity. If rtla fails to move itself away it is not that of a problem as this is an automatic measure. Link: https://lkml.kernel.org/r/c54304d90c777310fb85a3e658d1449173759aab.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Add --house-keeping option

2023-06-13T20:26:03+00:00

To avoid having rtla interfering with the measurement threads, add an option for the user to set the CPUs in which rtla should run. For instance: # rtla timerlat top -H 0 -c 1-7 Will place rtla in the CPU 0, while running the measurement threads in the CPU 1-7. Link: https://lkml.kernel.org/r/6a6c78a579a96ba8b02ae67ee1e0ba2cb5e03c4a.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Suggested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Add -C cgroup support

2023-06-13T20:25:13+00:00

The -C option sets a cgroup to the tracer's threads. If the -C option is passed without arguments, the tracer's thread will inherit rtla's cgroup. Otherwise, the threads will be placed on the cgroup passed to the option. Link: https://lkml.kernel.org/r/cb051477331d292f17c08bf1d66f0e0384bbe5a5.1686066600.git.bristot@kernel.org Cc: William White Cc: Jonathan Corbet Tested-by: Juri Lelli Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)