Re: [PATCH 0/1] perf report: append inlines to non-dwarf callchains

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	Milian Wolff <milian.wolff@kdab.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Andrii Nakryiko <andrii.nakryiko@gmail.com>
Subject: Re: [PATCH 0/1] perf report: append inlines to non-dwarf callchains
Date: Wed, 22 Mar 2023 16:44:20 -0300	[thread overview]
Message-ID: <ZBtalEw0qKQFlVWR@kernel.org> (raw)
In-Reply-To: <CAM9d7ch9NjnaB5dB6fO7WKdwPd8M9DmNpdu4-V-8R+96ssxMvA@mail.gmail.com>

Em Wed, Mar 22, 2023 at 11:18:49AM -0700, Namhyung Kim escreveu:
> On Fri, Mar 17, 2023 at 12:41 AM Artem Savkov <asavkov@redhat.com> wrote:
> >
> > On Thu, Mar 16, 2023 at 02:26:18PM -0700, Namhyung Kim wrote:
> > > Hello,
> > >
> > > On Thu, Mar 16, 2023 at 6:36 AM Artem Savkov <asavkov@redhat.com> wrote:
> > > >
> > > > In an email to Arnaldo Andrii Nakryiko suggested that perf can get
> > > > information about inlined functions from dwarf when available and then
> > > > add it to userspace stacktraces even in framepointer or lbr mode.
> > > > Looking closer at perf it turned out all required bits and pieces are
> > > > already there and inline information can be easily added to both
> > > > framepointer and lbr callchains by adding an append_inlines() call to
> > > > add_callchain_ip().
> > >
> > > Looks great!  Have you checked it with perf report -g callee ?
> > > I'm not sure the ordering of inlined functions is maintained
> > > properly.  Maybe you can use --no-children too to simplify
> > > the output.
> >
> > Thanks for the suggestion. I actually have another test program with
> > functions being numbered rather than (creatively) named, so it might be
> > easier to use it to figure out ordering. Here's the code:
> 
> Yep, looks good.
> 
> Acked-by: Namhyung Kim <namhyung@kernel.org>

So, I'll apply this shorter patch instead, ok?

- Arnaldo

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 803c9d1803dd26ef..abf6167f28217fe6 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -44,6 +44,7 @@
 #include <linux/zalloc.h>
 
 static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock);
+static int append_inlines(struct callchain_cursor *cursor, struct map_symbol *ms, u64 ip);
 
 static struct dso *machine__kernel_dso(struct machine *machine)
 {
@@ -2322,6 +2323,10 @@ static int add_callchain_ip(struct thread *thread,
 	ms.maps = al.maps;
 	ms.map = al.map;
 	ms.sym = al.sym;
+
+	if (append_inlines(cursor, &ms, ip) == 0)
+		return 0;
+
 	srcline = callchain_srcline(&ms, al.addr);
 	return callchain_cursor_append(cursor, ip, &ms,
 				       branch, flags, nr_loop_iter,
