diff options
Diffstat (limited to 'Documentation/tools/rtla')
| -rw-r--r-- | Documentation/tools/rtla/common_options.rst | 11 | ||||
| -rw-r--r-- | Documentation/tools/rtla/common_osnoise_options.rst | 4 | ||||
| -rw-r--r-- | Documentation/tools/rtla/common_timerlat_description.rst | 10 | ||||
| -rw-r--r-- | Documentation/tools/rtla/common_timerlat_options.rst | 18 | ||||
| -rw-r--r-- | Documentation/tools/rtla/rtla-timerlat.rst | 9 |
5 files changed, 40 insertions, 12 deletions
diff --git a/Documentation/tools/rtla/common_options.rst b/Documentation/tools/rtla/common_options.rst index aeb91ff3bd68..2dc1575210aa 100644 --- a/Documentation/tools/rtla/common_options.rst +++ b/Documentation/tools/rtla/common_options.rst @@ -14,10 +14,6 @@ Print debug info. -**-t**, **--trace**\[*=file*] - - Save the stopped trace to [*file|osnoise_trace.txt*]. - **-e**, **--event** *sys:event* Enable an event in the trace (**-t**) session. The argument can be a specific event, e.g., **-e** *sched:sched_switch*, or all events of a system group, e.g., **-e** *sched*. Multiple **-e** are allowed. It is only active when **-t** or **-a** are set. @@ -50,6 +46,13 @@ Set 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. +**--warm-up** *s* + + After starting the workload, let it run for *s* seconds before starting collecting the data, allowing the system to warm-up. Statistical data generated during warm-up is discarded. + +**--trace-buffer-size** *kB* + Set the per-cpu trace buffer size in kB for the tracing output. + **-h**, **--help** Print help menu. diff --git a/Documentation/tools/rtla/common_osnoise_options.rst b/Documentation/tools/rtla/common_osnoise_options.rst index f792ca58c211..d73de2d58f5f 100644 --- a/Documentation/tools/rtla/common_osnoise_options.rst +++ b/Documentation/tools/rtla/common_osnoise_options.rst @@ -25,3 +25,7 @@ Specify the minimum delta between two time reads to be considered noise. The default threshold is *5 us*. + +**-t**, **--trace** \[*file*] + + Save the stopped trace to [*file|osnoise_trace.txt*]. diff --git a/Documentation/tools/rtla/common_timerlat_description.rst b/Documentation/tools/rtla/common_timerlat_description.rst index 321201cb8597..49fcae3ffdec 100644 --- a/Documentation/tools/rtla/common_timerlat_description.rst +++ b/Documentation/tools/rtla/common_timerlat_description.rst @@ -6,5 +6,13 @@ debugging of operating system timer latency. The *timerlat* tracer outputs information in two ways. It periodically prints the timer latency at the timer *IRQ* handler and the *Thread* -handler. It also enable the trace of the most relevant information via +handler. It also enables the trace of the most relevant information via **osnoise:** tracepoints. + +The **rtla timerlat** tool sets the options of the *timerlat* tracer +and collects and displays a summary of the results. By default, +the collection is done synchronously in kernel space using a dedicated +BPF program attached to the *timerlat* tracer. If either BPF or +the **osnoise:timerlat_sample** tracepoint it attaches to is +unavailable, the **rtla timerlat** tool falls back to using tracefs to +process the data asynchronously in user space. diff --git a/Documentation/tools/rtla/common_timerlat_options.rst b/Documentation/tools/rtla/common_timerlat_options.rst index d3255ed70195..10dc802f8d65 100644 --- a/Documentation/tools/rtla/common_timerlat_options.rst +++ b/Documentation/tools/rtla/common_timerlat_options.rst @@ -22,17 +22,33 @@ Save the stack trace at the *IRQ* if a *Thread* latency is higher than the argument in us. +**-t**, **--trace** \[*file*] + + Save the stopped trace to [*file|timerlat_trace.txt*]. + **--dma-latency** *us* Set the /dev/cpu_dma_latency to *us*, aiming to bound exit from idle latencies. *cyclictest* sets this value to *0* by default, use **--dma-latency** *0* to have similar results. +**--deepest-idle-state** *n* + Disable idle states higher than *n* for cpus that are running timerlat threads to + reduce exit from idle latencies. If *n* is -1, all idle states are disabled. + On exit from timerlat, the idle state setting is restored to its original state + before running timerlat. + + Requires rtla to be built with libcpupower. + +**-k**, **--kernel-threads** + + Use timerlat kernel-space threads, in contrast of **-u**. + **-u**, **--user-threads** Set timerlat to run without a workload, and then dispatches user-space workloads to wait on the timerlat_fd. Once the workload is awakes, it goes to sleep again adding so the measurement for the kernel-to-user and user-to-kernel to the tracer - output. + output. **--user-threads** will be used unless the user specify **-k**. **-U**, **--user-load** diff --git a/Documentation/tools/rtla/rtla-timerlat.rst b/Documentation/tools/rtla/rtla-timerlat.rst index 44a49e6f302b..20e2d259467f 100644 --- a/Documentation/tools/rtla/rtla-timerlat.rst +++ b/Documentation/tools/rtla/rtla-timerlat.rst @@ -16,13 +16,10 @@ DESCRIPTION .. include:: common_timerlat_description.rst -The *timerlat* tracer outputs information in two ways. It periodically -prints the timer latency at the timer *IRQ* handler and the *Thread* handler. -It also provides information for each noise via the **osnoise:** tracepoints. The **rtla timerlat top** mode displays a summary of the periodic output -from the *timerlat* tracer. The **rtla hist hist** mode displays a histogram -of each tracer event occurrence. For further details, please refer to the -respective man page. +from the *timerlat* tracer. The **rtla timerlat hist** mode displays +a histogram of each tracer event occurrence. For further details, please +refer to the respective man page. MODES ===== |