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path: root/tools/tracing/rtla/src/osnoise.c
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2025-03-26rtla: Always set all tracer optionsTomas Glozar
rtla currently only sets tracer options that are explicitly set by the user, with the exception of OSNOISE_WORKLOAD. This leads to improper behavior in case rtla is run with those options not set to the default value. rtla does reset them to the original value upon exiting, but that does not protect it from starting with non-default values set either by an improperly exited rtla or by another user of the tracers. For example, after running this command: $ echo 1 > /sys/kernel/tracing/osnoise/stop_tracing_us all runs of rtla will stop at the 1us threshold, even if not requested by the user: $ rtla osnoise hist Index CPU-000 CPU-001 1 8 5 2 5 9 3 1 2 4 6 1 5 2 1 6 0 1 8 1 1 12 0 1 14 1 0 15 1 0 over: 0 0 count: 25 21 min: 1 1 avg: 3.68 3.05 max: 15 12 rtla osnoise hit stop tracing Fix the problem by setting the default value for all tracer options if the user has not provided their own value. For most of the options, it's enough to just drop the if clause checking for the value being set. For cpus, "all" is used as the default value, and for osnoise default period and runtime, default values of the osnoise_data variable in trace_osnoise.c are used. Cc: Luis Goncalves <lgoncalv@redhat.com> Link: https://lore.kernel.org/20250320092500.101385-5-tglozar@redhat.com Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode") Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode") Fixes: a828cd18bc4a ("rtla: Add timerlat tool and timelart top mode") Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode") Signed-off-by: Tomas Glozar <tglozar@redhat.com> Reviewed-by: John Kacur <jkacur@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-03-26rtla/osnoise: Set OSNOISE_WORKLOAD to trueTomas Glozar
If running rtla osnoise with NO_OSNOISE_WORKLOAD, it reports no samples: $ echo NO_OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options $ rtla osnoise hist -d 10s Index over: 0 count: 0 min: 0 avg: 0 max: 0 This situation can also happen when running rtla-osnoise after an improperly exited rtla-timerlat run. Set OSNOISE_WORKLOAD in rtla-osnoise, too, similarly to what we already did for timerlat in commit 217f0b1e990e ("rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads") and commit d8d866171a41 ("rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads"). Note that there is no user workload mode for rtla-osnoise yet, so OSNOISE_WORKLOAD is always set to true. Cc: Luis Goncalves <lgoncalv@redhat.com> Link: https://lore.kernel.org/20250320092500.101385-4-tglozar@redhat.com Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode") Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode") Signed-off-by: Tomas Glozar <tglozar@redhat.com> Reviewed-by: John Kacur <jkacur@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-03-26rtla: Unify apply_config between top and histTomas Glozar
The functions osnoise_top_apply_config and osnoise_hist_apply_config, as well as timerlat_top_apply_config and timerlat_hist_apply_config, are mostly the same. Move common part from them into separate functions osnoise_apply_config and timerlat_apply_config. For rtla-timerlat, also unify params->user_hist and params->user_top into one field called params->user_data, and move several fields used only by timerlat-top into the top-only section of struct timerlat_params. Cc: Luis Goncalves <lgoncalv@redhat.com> Link: https://lore.kernel.org/20250320092500.101385-3-tglozar@redhat.com Signed-off-by: Tomas Glozar <tglozar@redhat.com> Reviewed-by: John Kacur <jkacur@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-03-26rtla/osnoise: Unify params structTomas Glozar
Instead of having separate structs osnoise_top_params and osnoise_hist_params, use one struct osnoise_params for both. This allows code using the structs to be shared between osnoise-top and osnoise-hist. Cc: Luis Goncalves <lgoncalv@redhat.com> Link: https://lore.kernel.org/20250320092500.101385-2-tglozar@redhat.com Signed-off-by: Tomas Glozar <tglozar@redhat.com> Reviewed-by: John Kacur <jkacur@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-24rtla: Add function to report missed eventsTomas Glozar
Add osnoise_report_missed_events to be used to report the number of missed events either during or after an osnoise or timerlat run. Also, display the percentage of missed events compared to the total number of received events. If an unknown number of missed events was reported during the run, the entire number of missed events is reported as unknown. Cc: John Kacur <jkacur@redhat.com> Cc: Luis Goncalves <lgoncalv@redhat.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/20250123142339.990300-4-tglozar@redhat.com Signed-off-by: Tomas Glozar <tglozar@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-24tools/rtla: Add osnoise_trace_is_off()Costa Shulyupin
All of the users of trace_is_off() passes in &record->trace as the second parameter, where record is a pointer to a struct osnoise_tool. This record could be NULL and there is a hidden dependency that the trace field is the first field to allow &record->trace to work with a NULL record pointer. In order to make this code a bit more robust, as record shouldn't be dereferenced if it is NULL, even if the code does work, create a new function called osnoise_trace_is_off() that takes the pointer to a struct osnoise_tool as its second parameter. This way it can properly test if it is NULL before it dereferences it. The old function trace_is_off() is removed and the function osnoise_trace_is_off() is added into osnoise.c which is what the struct osnoise_tool is associated with. Cc: John Kacur <jkacur@redhat.com> Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Cc: Eder Zulian <ezulian@redhat.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Tomas Glozar <tglozar@redhat.com> Cc: Gabriele Monaco <gmonaco@redhat.com> Link: https://lore.kernel.org/20250115180055.2136815-1-costa.shul@redhat.com Signed-off-by: Costa Shulyupin <costa.shul@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-24rtla/osnoise: Distinguish missing workload optionTomas Glozar
osnoise_set_workload returns -1 for both missing OSNOISE_WORKLOAD option and failure in setting the option. Return -1 for missing and -2 for failure to distinguish them. Cc: stable@vger.kernel.org Cc: John Kacur <jkacur@redhat.com> Cc: Luis Goncalves <lgoncalv@redhat.com> Link: https://lore.kernel.org/20250107144823.239782-2-tglozar@redhat.com Signed-off-by: Tomas Glozar <tglozar@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-06-13rtla/timerlat_top: Add timerlat user-space supportDaniel Bristot de Oliveira
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 <chwhite@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Tested-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-13rtla: Add hwnoise toolDaniel Bristot de Oliveira
The hwnoise tool is a special mode for the osnoise top tool. hwnoise dispatches the osnoise tracer and displays a summary of the noise. The difference is that it runs the tracer with the OSNOISE_IRQ_DISABLE option set, thus only allowing only hardware-related noise, resulting in a simplified output. hwnoise has the same features of osnoise. An example of the tool's output: # rtla hwnoise -c 1-11 -T 1 -d 10m -q Hardware-related Noise duration: 0 00:10:00 | time is in us CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI 1 #599 599000000 138 99.99997 3 3 4 74 2 #599 599000000 85 99.99998 3 3 4 75 3 #599 599000000 86 99.99998 4 3 6 75 4 #599 599000000 81 99.99998 4 4 2 75 5 #599 599000000 85 99.99998 2 2 2 75 Link: https://lkml.kernel.org/r/2d6f49a6f3a4f8b51b2c806458b1cff71ad4d014.1675805361.git.bristot@kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-12-09rtla: Fix exit status when returning from calls to usage()John Kacur
rtla_usage(), osnoise_usage() and timerlat_usage() all exit with an error status. However when these are called from help, they should exit with a non-error status. Fix this by passing the exit status to the functions. Note, although we remove the subsequent call to exit after calling usage, we leave it in at the end of a function to suppress the compiler warning "control reaches end of a non-void function". Link: https://lkml.kernel.org/r/20221107144313.22470-1-jkacur@redhat.com Signed-off-by: John Kacur <jkacur@redhat.com> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-03-15rtla/osnoise: Add support to adjust the tracing_threshDaniel Bristot de Oliveira
osnoise uses the tracing_thresh parameter to define the delta between two reads of the time to be considered a noise. Add support to get and set the tracing_thresh from osnoise tools. Link: https://lkml.kernel.org/r/715ad2a53fd40e41bab8c3f1214c1a94e12fb595.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-25rtla/osnoise: Fix error message when failing to enable trace instanceDaniel Bristot de Oliveira
When a trace instance creation fails, tools are printing: Could not enable -> osnoiser <- tracer for tracing Print the actual (and correct) name of the tracer it fails to enable. Link: https://lkml.kernel.org/r/53ef0582605af91eca14b19dba9fc9febb95d4f9.1645206561.git.bristot@kernel.org Fixes: b1696371d865 ("rtla: Helper functions for rtla") Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-02-08rtla: Fix segmentation fault when failing to enable -tDaniel Bristot de Oliveira
rtla osnoise and timerlat are causing a segmentation fault when running with the --trace option on a kernel that does not support multiple instances. For example: [root@f34 rtla]# rtla osnoise top -t failed to enable the tracer osnoise Could not enable osnoiser tracer for tracing Failed to enable the trace instance Segmentation fault (core dumped) This error happens because the exit code of the tools is trying to destroy the trace instance that failed to be created. Make osnoise_destroy_tool() aware of possible NULL osnoise_tool *, and do not attempt to destroy it. This also simplifies the exit code. Link: https://lkml.kernel.org/r/5660a2b6bf66c2655842360f2d7f6b48db5dba23.1644327249.git.bristot@kernel.org Suggested-by: Steven Rostedt <rostedt@goodmis.org> Fixes: 1eceb2fc2ca5 ("rtla/osnoise: Add osnoise top mode") Fixes: 829a6c0b5698 ("rtla/osnoise: Add the hist mode") Fixes: a828cd18bc4a ("rtla: Add timerlat tool and timelart top mode") Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-13rtla/osnoise: Add the hist modeDaniel Bristot de Oliveira
The rtla osnoise hist tool collects all osnoise:sample_threshold occurrence in a histogram, displaying the results in a user-friendly way. The tool also allows many configurations of the osnoise tracer and the collection of the tracer output. Here is one example of the rtla osnoise hist tool output: ---------- %< ---------- [root@f34 ~]# rtla osnoise hist --bucket-size 10 --entries 100 -c 0-8 -d 1M -r 9000 -P F:1 # RTLA osnoise histogram # Time unit is microseconds (us) # Duration: 0 00:01:00 Index CPU-000 CPU-001 CPU-002 CPU-003 CPU-004 CPU-005 CPU-006 CPU-007 CPU-008 0 430 434 352 455 440 463 467 436 484 10 88 88 92 141 120 100 126 166 100 20 19 7 12 22 8 8 13 13 16 30 6 0 2 0 1 2 2 1 0 50 0 0 0 0 0 0 1 0 0 over: 0 0 0 0 0 0 0 0 0 count: 543 529 458 618 569 573 609 616 600 min: 0 0 0 0 0 0 0 0 0 avg: 0 0 0 0 0 0 0 0 0 max: 30 20 30 20 30 30 50 30 20 ---------- >% ---------- Running - rtla osnoise hist --help provides information about the available options. Link: https://lkml.kernel.org/r/c68060544de89b8b62510ed91c7369f162eb465b.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla/osnoise: Add osnoise top modeDaniel Bristot de Oliveira
The rtla osnoise tool is an interface for the osnoise tracer. The osnoise tracer dispatches a kernel thread per-cpu. These threads read the time in a loop while with preemption, softirqs and IRQs enabled, thus allowing all the sources of osnoise during its execution. The osnoise threads take note of the entry and exit point of any source of interferences, increasing a per-cpu interference counter. The osnoise tracer also saves an interference counter for each source of interference. The rtla osnoise top mode displays information about the periodic summary from the osnoise tracer. One example of rtla osnoise top output is: [root@alien ~]# rtla osnoise top -c 0-3 -d 1m -q -r 900000 -P F:1 Operating System Noise duration: 0 00:01:00 | time is in us CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI IRQ Softirq Thread 0 #58 52200000 1031 99.99802 91 60 0 0 52285 0 101 1 #59 53100000 5 99.99999 5 5 0 9 53122 0 18 2 #59 53100000 7 99.99998 7 7 0 8 53115 0 18 3 #59 53100000 8274 99.98441 277 23 0 9 53778 0 660 "rtla osnoise top --help" works and provide information about the available options. Link: https://lkml.kernel.org/r/0d796993abf587ae5a170bb8415c49368d4999e1.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13rtla: Add osnoise toolDaniel Bristot de Oliveira
The osnoise tool is the interface for the osnoise tracer. The osnoise tool will have multiple "modes" with different outputs. At this point, no mode is included. The osnoise.c includes the osnoise_context abstraction. It serves to read-save-change-restore the default values from tracing/osnoise/ directory. When the context is deleted, the default values are restored. It also includes some other helper functions for managing osnoise tracer sessions. With these bits and pieces in place, we can start adding some functionality to rtla. Link: https://lkml.kernel.org/r/2d44c21ff561f503b4c7b1813892761818118460.1639158831.git.bristot@kernel.org Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>