Messages in this thread | | | Date | Wed, 20 May 2015 09:30:52 +0900 | From | Namhyung Kim <> | Subject | Re: [RFC PATCH v3 00/37] perf tools: introduce 'perf bpf' command to load eBPF programs. |
| |
On Tue, May 19, 2015 at 06:10:33PM -0300, Arnaldo Carvalho de Melo wrote: > Em Tue, May 19, 2015 at 01:46:10PM -0700, Alexei Starovoitov escreveu: > > On 5/19/15 9:40 AM, Arnaldo Carvalho de Melo wrote: > > >Em Wed, May 20, 2015 at 01:04:48AM +0900, Namhyung Kim escreveu: > > >>If we go with 'perf record' rather than 'perf bpf record', I agree > > >>that --event option is more natural than --filter. The --event option > > >>says that it will record - or enable, at least - a (kprobe) event for > > >>bpf programs in it and then do something with it. :) > > >> > > >>Maybe something like this? > > >> > > >> perf record --event bpf:/path/to/object > > > > > >The syntax maybe one of many, say if it sees a ".o" suffix in the even > > >name, look if the provided event name is a file and if this file has the > > >ELF header, whatever. > > > > agree. 'bpf:' prefix is redundant. > > I would say unnecessarily exposing an implementation detail :-) > > > To me the following syntax is fine: > > perf record --event bpf_file.o > > Agreed, for something pre-compiled. > > > In the future it can support automatically: > > perf record --event bpf_file.c > > Right, to compile it, then use the resulting bpf_file.o just like in the > first case, then, on another patch, cache it and next time just check > that the contents of the file hasn't changed, so the .o file can be > used, i.e. ccache like stuff. > > > Wang, thoughts? > > > > >>Oh, this looks like an interesting approach.. are you saying something > > >>like below? > > > > > >No, those are way too many steps :-) > > > > > >What 'perf script' does? Right now you can ask for a script to run and > > >it will both start 'perf record' with the proper events, and then > > >"immediately" consume it, piping the output of the 'record' "script" to > > >the consumer, that is 'perf script' itself running an interpreter, perl > > >or python. > > > > if you're proposing to do something like: > > perf script bpf_file.c > > that will do event creation, filtering, aggregation, reporting > > and printing results, then it's fine. > > This is pretty much what I thought 'perf bpf run' will do. > > Agreed, that is what I think should be done, parts of what is in > bpf.file.c are related to the data collection, some are for filtering, > and parts are for reporting, etc.
Looks great! :)
> > This all should use infrastructure in perf for symbol resolving, > callcahins, etc.
But then we need to stabilize libperf APIs IMHO. :)
Thanks, Namhyung
| |