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From:   Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Date:   Mon, 11 Mar 2019 18:17:09 -0300
To:     Song Liu <songliubraving@fb.com>
Cc:     "bpf@vger.kernel.org" <bpf@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Kernel Team <Kernel-team@fb.com>,
        "peterz@infradead.org" <peterz@infradead.org>,
        "acme@redhat.com" <acme@redhat.com>,
        "jolsa@kernel.org" <jolsa@kernel.org>,
        "namhyung@kernel.org" <namhyung@kernel.org>,
        "sdf@fomichev.me" <sdf@fomichev.me>
Subject: Re: [PATCH v8 perf,bpf 10/15] perf-top: add option --no-bpf-event
Message-ID: <20190311211709.GA4939@kernel.org>
References: <20190311195555.889995-1-songliubraving@fb.com>
 <20190311195555.889995-11-songliubraving@fb.com>
 <B1C5BA9A-20FB-46BA-A4D8-759CBA1C9ABD@fb.com>
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Em Mon, Mar 11, 2019 at 09:07:20PM +0000, Song Liu escreveu:
> 
> 
> > On Mar 11, 2019, at 12:55 PM, Song Liu <songliubraving@fb.com> wrote:
> > 
> > bpf events should be tracked by default for perf-top. This patch makes it
> > on by default, and adds option to disable bpf events.
> > 
> > Signed-off-by: Song Liu <songliubraving@fb.com>
> > ---
> > tools/perf/builtin-top.c | 3 +++
> > tools/perf/util/top.h    | 1 +
> > 2 files changed, 4 insertions(+)
> > 
> > diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> > index 27d8d42e0a4d..ccdf5689452f 100644
> > --- a/tools/perf/builtin-top.c
> > +++ b/tools/perf/builtin-top.c
> > @@ -1492,6 +1492,7 @@ int cmd_top(int argc, const char **argv)
> > 		    "Display raw encoding of assembly instructions (default)"),
> > 	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
> > 		    "Enable kernel symbol demangling"),
> > +	OPT_BOOLEAN(0, "no-bpf-event", &top.no_bpf_event, "do not record bpf events"),
> > 	OPT_STRING(0, "objdump", &top.annotation_opts.objdump_path, "path",
> > 		    "objdump binary to use for disassembly and annotations"),
> > 	OPT_STRING('M', "disassembler-style", &top.annotation_opts.disassembler_style, "disassembler style",
> > @@ -1651,6 +1652,8 @@ int cmd_top(int argc, const char **argv)
> > 		signal(SIGWINCH, winch_sig);
> > 	}
> > 
> > +	top.record_opts.bpf_event = !top.no_bpf_event;
> > +
> > 	status = __cmd_top(&top);
> > 
> > out_delete_evlist:
> > diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
> > index 19f95eaf75c8..862a37bd27ea 100644
> > --- a/tools/perf/util/top.h
> > +++ b/tools/perf/util/top.h
> > @@ -32,6 +32,7 @@ struct perf_top {
> > 	bool		   use_tui, use_stdio;
> > 	bool		   vmlinux_warned;
> > 	bool		   dump_symtab;
> > +	bool		   no_bpf_event;
> > 	struct hist_entry  *sym_filter_entry;
> > 	struct perf_evsel  *sym_evsel;
> > 	struct perf_session *session;
> > -- 
> > 2.17.1
> > 
> 
> Hi Arnaldo, 
> 
> Currently, we have bpf-event default OFF for perf-record, with option to 
> turn it ON; while bpf-event is default ON for perf-top, with option to 
> turn if OFF. I think this is a little confusing. 
> 
> How about we set them both to default ON, and add option to turn it OFF?

Agreed.

> I think we still have time to make the change. 
> 
> Thanks,
> Song
> 
> 

-- 

- Arnaldo