diff options
| author | Beau Belgrave <beaub@linux.microsoft.com> | 2023-06-14 09:33:36 -0700 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-06-14 13:43:27 -0400 |
| commit | 0113d4615dbf053ae9a7a1e0acbc6652713af01f (patch) | |
| tree | cac6ffcf8c67bdf74a394b4a16d5df6b1c674b98 /Documentation | |
| parent | 61701242e86f0b509a0f5f9deb226bedfc8dfab7 (diff) | |
tracing/user_events: Document auto-cleanup and remove dyn_event refs
Now user_events auto-cleanup upon the last reference by default. This
makes it not possible to use the dynamics event file via tracefs.
Document that auto-cleanup is enabled by default and remove the refernce
to /sys/kernel/tracing/dynamic_events file to make this clear.
Link: https://lkml.kernel.org/r/20230614163336.5797-7-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/trace/user_events.rst | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/Documentation/trace/user_events.rst b/Documentation/trace/user_events.rst index f79987e16cf4..e7b07313550a 100644 --- a/Documentation/trace/user_events.rst +++ b/Documentation/trace/user_events.rst @@ -14,10 +14,6 @@ Programs can view status of the events via /sys/kernel/tracing/user_events_status and can both register and write data out via /sys/kernel/tracing/user_events_data. -Programs can also use /sys/kernel/tracing/dynamic_events to register and -delete user based events via the u: prefix. The format of the command to -dynamic_events is the same as the ioctl with the u: prefix applied. - Typically programs will register a set of events that they wish to expose to tools that can read trace_events (such as ftrace and perf). The registration process tells the kernel which address and bit to reflect if any tool has @@ -144,6 +140,9 @@ its name. Delete will only succeed if there are no references left to the event (in both user and kernel space). User programs should use a separate file to request deletes than the one used for registration due to this. +**NOTE:** By default events will auto-delete when there are no references left +to the event. Flags in the future may change this logic. + Unregistering ------------- If after registering an event it is no longer wanted to be updated then it can |