Messages in this thread |  | | Date | Thu, 23 Oct 2014 11:24:22 +0530 | From | Srikar Dronamraju <> | Subject | Re: [PATCH v3 5/5] perf/sdt: Add support to perf record to trace SDT events |
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* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> [2014-10-22 18:41:58]:
> (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 :) > 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;) >
I am somehow not able to figure out how perf probe comes into the current workflow.
I think the current design was 1. perf sdt-cache --add <file> (only once per file) 2. perf record -e <sdt-event>
So what is the additional thing that perf probe does or Is it going to replace any of the above steps?
-- Thanks and Regards Srikar Dronamraju
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