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| author | Tom Zanussi <zanussi@kernel.org> | 2020-04-03 22:31:21 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-06-01 15:22:30 +0300 |
| commit | 2d19bd79ae6509858582a9cade739c2e9a4fdca8 (patch) | |
| tree | 7612f1c6d4821e70b8b69d91a0608ae68c4d3413 /kernel/trace/trace_events.c | |
| parent | 16b585fe71924b3aebaef5548a291021efaf7c7f (diff) | |
| download | linux-2d19bd79ae6509858582a9cade739c2e9a4fdca8.tar.xz | |
tracing: Add hist_debug trace event files for histogram debugging
Add a new "hist_debug" file for each trace event, which when read will
dump out a bunch of internal details about the hist triggers defined
on that event.
This is normally off but can be enabled by saying 'y' to the new
CONFIG_HIST_TRIGGERS_DEBUG config option.
This is in support of the new Documentation file describing histogram
internals, Documentation/trace/histogram-design.rst, which was
requested by developers trying to understand the internals when
extending or making use of the hist triggers for higher-level tools.
The histogram-design.rst documentation refers to the hist_debug files
and demonstrates their use with output in the test examples.
Link: http://lkml.kernel.org/r/77914c22b0ba493d9783c53bbfbc6087d6a7e1b1.1585941485.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events.c')
| -rw-r--r-- | kernel/trace/trace_events.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 242f59e7f17d..f6f55682d3e2 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2209,6 +2209,10 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file) trace_create_file("hist", 0444, file->dir, file, &event_hist_fops); #endif +#ifdef CONFIG_HIST_TRIGGERS_DEBUG + trace_create_file("hist_debug", 0444, file->dir, file, + &event_hist_debug_fops); +#endif trace_create_file("format", 0444, file->dir, call, &ftrace_event_format_fops); |