Re: [PATCH v3 5/5] perf/sdt: Add support to perf record to trace SDT events

[Hemant Kumar <hemant at linux dot vnet dot ibm dot com>]

On 10/22/2014 03:11 PM, Masami Hiramatsu wrote:
> (2014/10/22 17:20), Hemant Kumar wrote:
> > > >  From "file_sdt_ent" we will find out the file name.
> > > > Convert this sdt note into a perf event and then write this into uprobe_events
> > > > file to be able to record the event.
> > > > Then, corresponding entries are added to uprobe_events file for
> > > > the SDT events.
> > > > After recording is done, these events are silently deleted from uprobe_events
> > > > file. The uprobe_events file is present in debugfs/tracing directory.
> > > >
> > > > To support the addition and deletion of SDT events to/from uprobe_events
> > > > file, a record_sdt struct is maintained which has the event data.
> > > OK, I have some comments on this.
> > >
> > > > An example usage:
> > > >
> > > > # ./perf record -e %user_app:fun_start -aR /home/user_app
> > > At first, I'd like to add SDT support for adding probes too, like below;
> > >
> > > ./perf probe -a '%user_app:fun_start $vars'
> > But I think, previously we discussed that we won't be having "perf
> > probe" for SDT events.
> > We list them and probe/trace them using "perf record" directly.
> Right, sorry for confusing you. I meant that I'd like to support SDT on both of
> perf-record and perf-probe :)

I plan to do this and add this subsequently but will it be okay if we go 
with the current
implementation for the time being?

What do you think?

> And even if we'll hide sdt related events via perf, users can access it via ftrace.
> So, I doubt that we can completely hide them, in that case, honesty is the best way;)
>
> Thank you,

--
Thanks,
Hemant Kumar