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Date: Wed, 17 Jan 2024 10:45:46 +0800
From: Changbin Du <changbin.du@huawei.com>
To: Andi Kleen <ak@linux.intel.com>
CC: Changbin Du <changbin.du@huawei.com>, Peter Zijlstra
	<peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, Arnaldo Carvalho de
 Melo <acme@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Alexander
 Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>, Ian Rogers <irogers@google.com>, Adrian
 Hunter <adrian.hunter@intel.com>, <linux-kernel@vger.kernel.org>,
	<linux-perf-users@vger.kernel.org>
Subject: Re: [PATCH 0/3] perf: script: Intro capstone disasm engine to show
 instruction trace
Message-ID: <20240117024546.2npqrprazaobyogn@M910t>
References: <20240116113437.1507537-1-changbin.du@huawei.com>
 <87il3tl6zf.fsf@linux.intel.com>
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In-Reply-To: <87il3tl6zf.fsf@linux.intel.com>

On Tue, Jan 16, 2024 at 05:53:40AM -0800, Andi Kleen wrote:
> Changbin Du <changbin.du@huawei.com> writes:
> 
> > This series introduces capstone disassembler engine to print instructions of
> > Intel PT trace, which was printed via the XED tool.
> 
> FWIW at least on x86 in my experience capstone isn't that great an
> disassembler. I used it in another project and ran into many decoding bugs.
> They're mostly in obscure corners, but can be fairly annoying.
>
If so, I will preserve the old --xed option as an alternate.

> My other concern with your patchkit is that you change the default
> output formats. Since perf script is often used with scripts
> (as the name implies) there is a certain expectation that the output
> remains stable and parse-able. There are actually use cases where
> the raw bytes "insn" output is needed.
> 
> I would rather define new perf script output types for the new decoded output,
> but keep the old alone.
Agreed. What about these?
  - Add a new field 'insn_disam' to display decoded output.
  - Add params to '--insn-trace' option, that is '--insn-trace=[raw|disam]'.
    'raw' is the default value.

> 
> -Andi

-- 
Cheers,
Changbin Du