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| author | Tomas Glozar <tglozar@redhat.com> | 2025-03-11 12:49:36 +0100 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2025-04-14 10:42:55 -0600 |
| commit | 770840a0e7e88a5bd74e64f23e3a9021d045caef (patch) | |
| tree | 6b68d60dabd3e3257303efe08119c51ee8957fc2 | |
| parent | e7d3b24e3402db90d13725d89462af468df1a552 (diff) | |
Documentation/rtla: Include BPF sample collection
Add dependencies needed to build rtla with BPF sample collection support
to README, and document both ways of sample collection in the manpages.
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250311114936.148012-5-tglozar@redhat.com
| -rw-r--r-- | Documentation/tools/rtla/common_timerlat_description.rst | 8 | ||||
| -rw-r--r-- | tools/tracing/rtla/README.txt | 7 |
2 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/tools/rtla/common_timerlat_description.rst b/Documentation/tools/rtla/common_timerlat_description.rst index 8cd3e717baa8..49fcae3ffdec 100644 --- a/Documentation/tools/rtla/common_timerlat_description.rst +++ b/Documentation/tools/rtla/common_timerlat_description.rst @@ -8,3 +8,11 @@ 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 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/tools/tracing/rtla/README.txt b/tools/tracing/rtla/README.txt index dd5621038c55..43e98311d10f 100644 --- a/tools/tracing/rtla/README.txt +++ b/tools/tracing/rtla/README.txt @@ -13,6 +13,13 @@ RTLA depends on the following libraries and tools: - libtraceevent - libcpupower (optional, for --deepest-idle-state) +For BPF sample collection support, the following extra dependencies are +required: + + - libbpf 1.0.0 or later + - bpftool with skeleton support + - clang with BPF CO-RE support + It also depends on python3-docutils to compile man pages. For development, we suggest the following steps for compiling rtla: |