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From:   Namhyung Kim <namhyung@kernel.org>
Date:   Mon, 3 Apr 2023 22:18:47 -0700
Message-ID: <CAM9d7chDz9dNpB+vywLMNxyc9p=wLaJp4qUYwfu6y88tEDYLLw@mail.gmail.com>
Subject: Re: [PATCH v2 0/4] Support for llvm-addr2line
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Ian Rogers <irogers@google.com>,
        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>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        linux-perf-users@vger.kernel.org, llvm@lists.linux.dev
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Hi,

On Mon, Apr 3, 2023 at 1:24 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
>
> Em Mon, Apr 03, 2023 at 11:40:29AM -0700, Ian Rogers escreveu:
> > The addr2line command is started and then addresses piped to it. In
> > order to determine the end of a addr2lines output a ',' it output with
> > an expectation to get '??\n??:0\n' as a reply. llvm-addr2line differs
> > in that ',' generates a reply of ','.
> >
> > The approach detects and then caches the addr2line style. When records
> > are read the sentinel is detected appropriately.
> >
> > Comparing the output there is a little more inline data on my machine
> > with llvm-addr2line:
> > $ sudo perf record -a -g sleep 1
> > $ sudo perf report --addr2line=addr2line > a.txt
> > $ sudo perf report --addr2line=llvm-addr2line > b.txt
> > $ wc -l a.txt b.txt
> >   12386 a.txt
> >   12477 b.txt
> >
> > Some other small changes, switching to the api/io code to avoid file
> > streams wrapping the command's stdin/stdout. Ignore SIGPIPE for when
> > addr2line exits and writes fail.
> >
> > v2. Address review comments from Arnaldo and Namhyung, fixing a
> >     realloc error path, argument ordering and a comment.
>
> Added to local repo, build testing, will be in tmp.perf-tools-next soon.
>
> - Arnaldo
>
> > Ian Rogers (4):
> >   tools api: Add io__getline
> >   perf srcline: Simplify addr2line subprocess
> >   perf srcline: Support for llvm-addr2line
> >   perf srcline: Avoid addr2line SIGPIPEs

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung


> >
> >  tools/lib/api/io.h        |  45 ++++++++++
> >  tools/perf/tests/api-io.c |  36 ++++++++
> >  tools/perf/util/srcline.c | 171 +++++++++++++++++++++++---------------
> >  3 files changed, 184 insertions(+), 68 deletions(-)
> >
> > --
> > 2.40.0.348.gf938b09366-goog
> >
>
> --
>
> - Arnaldo