diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2025-05-08 09:56:39 -0400 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2025-05-09 15:19:11 -0400 |
| commit | 7b382efd5e8af4c0c67e70ad3fb599dcd2dc0b86 (patch) | |
| tree | aeaffefb516cc9edc88275c4a19a524cead16334 /kernel/trace/trace.h | |
| parent | 6956ea9fdcf706dc6201bf7146af188539eac9b1 (diff) | |
tracing: Allow the top level trace_marker to write into another instances
There are applications that have it hard coded to write into the top level
trace_marker instance (/sys/kernel/tracing/trace_marker). This can be
annoying if a profiler is using that instance for other work, or if it
needs all writes to go into a new instance.
A new option is created called "copy_trace_marker". By default, the top
level has this set, as that is the default buffer that writing into the
top level trace_marker file will go to. But now if an instance is created
and sets this option, all writes into the top level trace_marker will also
be written into that instance buffer just as if an application were to
write into the instance's trace_marker file.
If the top level instance disables this option, then writes to its own
trace_marker and trace_marker_raw files will not go into its buffer.
If no instance has this option set, then the write will return an error
and errno will contain ENODEV.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250508095639.39f84eda@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 86e9d7dcddba..bd084953a98b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -403,6 +403,7 @@ struct trace_array { struct trace_options *topts; struct list_head systems; struct list_head events; + struct list_head marker_list; struct trace_event_file *trace_marker_file; cpumask_var_t tracing_cpumask; /* only trace on set CPUs */ /* one per_cpu trace_pipe can be opened by only one user */ @@ -1384,6 +1385,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, C(MARKERS, "markers"), \ C(EVENT_FORK, "event-fork"), \ C(TRACE_PRINTK, "trace_printk_dest"), \ + C(COPY_MARKER, "copy_trace_marker"),\ C(PAUSE_ON_TRACE, "pause-on-trace"), \ C(HASH_PTR, "hash-ptr"), /* Print hashed pointer */ \ FUNCTION_FLAGS \ |