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Date:   Mon, 3 Apr 2023 17:24:30 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Ian Rogers <irogers@google.com>
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>,
        Namhyung Kim <namhyung@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
Subject: Re: [PATCH v2 0/4] Support for llvm-addr2line
Message-ID: <ZCs1/skb2XqDYrYF@kernel.org>
References: <20230403184033.1836023-1-irogers@google.com>
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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
> 
>  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