Re: [PATCH 2/2] perf, tools, script: Add support for printing assembler

From: Andi Kleen
Date: Mon Feb 29 2016 - 12:35:38 EST


> What kernel have you used for testing this? 4.5-rc? I'm having trouble
> with intel_pt with 4.5.0-rc4 :-\

Works for me (on -rc5). What problem do you see?

>
> And while this looks like a great feature to have, have you considered
> using what is in tools/perf/util/intel-pt-decoder/ somehow, so that we
> don't end up adding one more dependency on another external library?

This needs a text disassembler.

The PT decoder doesn't have a disassembler unfortunately. The kernel
instruction decoder is also not a text disassembler. Changing it to do
that would be a quite large project.

> It would be great if we could, if done that way, perhaps at some point
> we could stop using objdump somehow :-\

objdump does a lot of work to line up the source code correctly.
Reproducing it would be a lot of work in perf too, and need
large scales changes. Perhaps at some time, but not any time
soon.

-Andi