Re: [PATCH v7 04/17] tracing: add static function tracer support for MIPS

Wu Zhangjin
2009-11-10T01:00:34Z

Hi,

On Mon, 2009-11-09 at 16:26 -0800, David Daney wrote:
> Wu Zhangjin wrote:
>
> >
> > +ifndef CONFIG_FUNCTION_TRACER
> > cflags-y := -ffunction-sections
> > +else
> > +cflags-y := -mlong-calls
> > +endif
> > cflags-y += $(call cc-option, -mno-check-zero-division)
> >
>
> That doesn't make sense to me. Modules are already compiled with
> -mlong-calls. The only time you would need the entire kernel compiled
> with -mlong-calls is if the tracer were in a module. The logic here
> doesn't seem to reflect that.

Yes, I knew the module have gotten the -mlong-calls, Here we just want
to use -mlong-calls for the whole kernel, and then we get the same
_mcount stuff in the whole kernel, at last, we can use the same
scripts/recordmcount.pl and ftrace_make_nop & ftrace_make_call for the
dynamic ftracer.

And seems we only need to enable it for the dynamic one. So, I will
split it out into it's own patch later.

Thanks & Regards,
Wu Zhangjin