Re: [perf top] annotation doesn't work, libunwind doesn't seem to be working either

[Ingo Molnar <mingo@kernel.org>]

* Namhyung Kim <namhyung@kernel.org> wrote:

> On Wed, Apr 09, 2025 at 12:26:56AM -0300, Arnaldo Carvalho de Melo wrote:
> > On Mon, Apr 07, 2025 at 11:16:04PM -0700, Namhyung Kim wrote:
> > > On Mon, Apr 07, 2025 at 09:54:47PM -0300, Arnaldo Carvalho de Melo wrote:
> > > > A quick test here with perf top without setting the above ends up with
> > > > the behaviour that Ingo reported, no source code is shown and 's'
> > > > doesn't work. Then if I set it to use objdump:
> > 
> > > > root@number:~# perf config annotate.disassemblers=objdump
> > > > root@number:~# perf config annotate.disassemblers
> > > > annotate.disassemblers=objdump
> > > > root@number:~# cat ~/.perfconfig 
> > > > # this file is auto-generated.
> > > > [annotate]
> > > > 	disassemblers = objdump
> > > > root@number:~#
> > 
> > > > It takes longer to show the annotated output but there is source code
> > > > and 's' works.
> > 
> > > Thanks for chasing it down, we miss source line support in the disasm
> > > using capstone and libllvm.  We can add that later but for now we may
> > > refresh the result and force to objdump when source line is requested.
> > 
> > That is a good idea, I thought about it as well and will check how to do
> > it on top of what I have at:
> > 
> > https://web.git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/log/?h=perf-annotate%2bbuild
> 
> How about this?
> 
> 
> From ce37ae9008ec7c6ab66ee1b6632a3c51bc0802f3 Mon Sep 17 00:00:00 2001
> From: Namhyung Kim <namhyung@kernel.org>
> Date: Thu, 10 Apr 2025 13:42:16 -0700
> Subject: [PATCH] perf annotate: Fix source code annotate with objdump
> 
> Recently it uses llvm and capstone to speed up annotation or disassembly
> of instructions.  But they don't support source code view yet.  Until it
> fixed, we can force to use objdump for source code annotation.
> 
> To prevent performance loss, it's disabled by default and turned it on
> when user requests it in TUI by pressing 's' key.

That's a good compromise IMO, thank you for implementing it!

	Ingo