Re: [PATCH 1/3] perf tools: Allow vmlinux to fallback to kallsyms on NO_LIBELF=1

[Peter Zijlstra <peterz@infradead.org>]

On Fri, Nov 07, 2014 at 11:57:39PM +0900, Namhyung Kim wrote:

> > Why does this live in the minimal implementation; should we not always
> > discard ELF files with 0 symbols?
> > 
> > Suppose I have a vmlinux but removed all symbols from it; I want it to
> > fall back to kallsyms too.
> 
> I'm not sure I understood what you said correctly.  With this change,
> dso__load_kernel_sym() always ends up calling dso__load_kallsyms() since
> dso__load_vmlinux() will always return 0;
> 
> So I think you'll fall back to kallsyms even though you have a vmlinux
> with symbol.  This makes dso__load_sym() in the patch 2/3 simpler IMHO.

But why have it specific to the minimal elf thing? Why not discard any
DSO with 0 symbols and try the next option to acquire symbols?