> Thanks for clean up the synthetic event! > This looks good to me. > > Reviewed-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> No problem, thanks for the review! > So now are you trying to reuse synth event for user event? > Then I think you need to register a new dyn_event ops so > that histogram will not submit the event. A user events patch will get sent out soon, I'm finalizing some testing. User events will register it's own dyn_event ops and allow users the option to create, delete and view status of user events via the dynamic_events tracefs file (in addition to the user mode IOCTL/ABI). As probes attach to the user events the status of this is reflected in dynamic_events, which makes it easy for admins to see why one is busy, etc. It also makes it easy to verifying the system is working as expected with just a terminal. > BTW, how do you filter an event written by a user process? > Will you add an array of event id for the file data structure? The filtering would happen at the trace_event level, the only filtering at the user event level is if a probe has been enabled on the underlying trace_event or not. That is done via the shared page bits being cleared or set. Bits are updated as probe un/registrations occur. Users can advertise field values, offsets, etc as well as the print_fmt in the newer ABI/patch based on the feedback from LPC2021. These land in the trace_event fields and are viewable via tracefs like any other evnet. I hope that is enough to light up the history feature of trace_event. I am not familiar with it as much as you all. Thanks, -Beau
|