kernel/linux.git/Documentation/trace/histogram.rst, branch v7.0.10

Documentation: trace: histogram: Convert ftrace docs cross-reference

2025-09-18T17:49:26+00:00

In brief "Extended error information" section, details on error condition is referred to ftrace docs, which is written in :file: directive instead of a proper cross-reference. Convert it. Reviewed-by: Tom Zanussi Signed-off-by: Bagas Sanjaya Acked-by: Steven Rostedt (Google) Signed-off-by: Jonathan Corbet Message-ID: <20250916054202.582074-7-bagasdotme@gmail.com>

Documentation: trace: histogram: Fix histogram trigger subsection number order

2025-09-18T17:49:26+00:00

Section numbering in subsections of "Histogram Trigger Command" sections is inconsistent in order. In particular, "'hist' trigger examples" is erroneously numbered as 6.2, which is a leftover from b8df4a3634e08a ("tracing: Move hist trigger Documentation to histogram.txt"). Fix the order. Reviewed-by: Tom Zanussi Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Bagas Sanjaya Acked-by: Steven Rostedt (Google) Signed-off-by: Jonathan Corbet Message-ID: <20250916054202.582074-3-bagasdotme@gmail.com>

Documentation: Fix trace typos

2025-08-18T16:31:20+00:00

Fix typos. Signed-off-by: Bjorn Helgaas Reviewed-by: Randy Dunlap Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20250813200526.290420-9-helgaas@kernel.org

tracing: doc: fix "for a while" typo

2025-07-08T14:14:28+00:00

Signed-off-by: Ahelenia Ziemiańska Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/xygdnynf7m55p7d27ovzqtdjaa7pua3bxuk5c22cnmoovaji5e@tarta.nabijaczleweli.xyz

tracing: doc: Fix typo in ftrace histogram

2024-10-07T17:50:54+00:00

The Tracing > Histogram page contains a typo in the field display modifiers table. Signed-off-by: Gabriele Monaco Acked-by: Steven Rostedt (Google) Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20241003122334.44682-2-gmonaco@redhat.com

tracing: Rename stacktrace field to common_stacktrace

2023-05-24T03:38:23+00:00

The histogram and synthetic events can use a pseudo event called "stacktrace" that will create a stacktrace at the time of the event and use it just like it was a normal field. We have other pseudo events such as "common_cpu" and "common_timestamp". To stay consistent with that, convert "stacktrace" to "common_stacktrace". As this was used in older kernels, to keep backward compatibility, this will act just like "common_cpu" did with "cpu". That is, "cpu" will be the same as "common_cpu" unless the event has a "cpu" field. In which case, the event's field is used. The same is true with "stacktrace". Also update the documentation to reflect this change. Link: https://lore.kernel.org/linux-trace-kernel/20230523230913.6860e28d@rorschach.local.home Cc: Masami Hiramatsu Cc: Tom Zanussi Cc: Mark Rutland Signed-off-by: Steven Rostedt (Google)

Merge tag 'trace-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2023-02-23T18:20:49+00:00

Pull tracing updates from Steven Rostedt: - Add function names as a way to filter function addresses - Add sample module to test ftrace ops and dynamic trampolines - Allow stack traces to be passed from beginning event to end event for synthetic events. This will allow seeing the stack trace of when a task is scheduled out and recorded when it gets scheduled back in. - Add trace event helper __get_buf() to use as a temporary buffer when printing out trace event output. - Add kernel command line to create trace instances on boot up. - Add enabling of events to instances created at boot up. - Add trace_array_puts() to write into instances. - Allow boot instances to take a snapshot at the end of boot up. - Allow live patch modules to include trace events - Minor fixes and clean ups * tag 'trace-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits) tracing: Remove unnecessary NULL assignment tracepoint: Allow livepatch module add trace event tracing: Always use canonical ftrace path tracing/histogram: Fix stacktrace histogram Documententation tracing/histogram: Fix stacktrace key tracing/histogram: Fix a few problems with stacktrace variable printing tracing: Add BUILD_BUG() to make sure stacktrace fits in strings tracing/histogram: Don't use strlen to find length of stacktrace variables tracing: Allow boot instances to have snapshot buffers tracing: Add trace_array_puts() to write into instance tracing: Add enabling of events to boot instances tracing: Add creation of instances at boot command line tracing: Fix trace_event_raw_event_synth() if else statement samples: ftrace: Make some global variables static ftrace: sample: avoid open-coded 64-bit division samples: ftrace: Include the nospec-branch.h only for x86 tracing: Acquire buffer from temparary trace sequence tracing/histogram: Wrap remaining shell snippets in code blocks tracing/osnoise: No need for schedule_hrtimeout range bpf/tracing: Use stage6 of tracing to not duplicate macros ...

tracing/histogram: Fix stacktrace histogram Documententation

2023-02-16T18:49:39+00:00

Fix a small problem with the histogram specification in the Documentation, and change the example to show output using a stacktrace field rather than the global stacktrace. Link: https://lkml.kernel.org/r/f75f807dd4998249e513515f703a2ff7407605f4.1676063532.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (Google)

tracing/histogram: Wrap remaining shell snippets in code blocks

2023-02-07T17:41:11+00:00

Most shell command snippets (echo/cat) and their output are already in literal code blocks. However a few still isn't wrapped, in which the htmldocs output is ugly. Wrap the remaining unwrapped snippets, while also fix recent kernel test robot warnings. Link: https://lore.kernel.org/linux-trace-kernel/20230129031402.47420-1-bagasdotme@gmail.com Cc: Masami Hiramatsu Cc: Jonathan Corbet Link: https://lore.kernel.org/linux-doc/202301290253.LU5yIxcJ-lkp@intel.com/ Fixes: 88238513bb2671 ("tracing/histogram: Document variable stacktrace") Reported-by: kernel test robot Signed-off-by: Bagas Sanjaya Signed-off-by: Steven Rostedt (Google)

docs: ftrace: always use canonical ftrace path

2023-01-31T21:02:30+00:00

The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many parts of Documentation still reference this older debugfs path, so let's update them to avoid confusion. Signed-off-by: Ross Zwisler Reviewed-by: Steven Rostedt (Google) Link: https://lore.kernel.org/r/20230125213251.2013791-1-zwisler@google.com Signed-off-by: Jonathan Corbet