Re: [PATCH 1/4] Add support for userspace stacktraces in tracing/iter_ctrl

Peter Zijlstra
2008-10-26T13:29:42Z

On Sun, 2008-10-26 at 09:15 -0400, Frank Ch. Eigler wrote:
> "=?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?=" <fweisbec@gmail.com> writes:
>
> > [...]
> >> +/* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
> >> +
> >> +struct stack_frame {
> >> + const void __user *next_fp;
> >> + unsigned long return_address;
> >> +};
> > [...]
>
> To what extent does this actually work, and on which architectures?
> While the kernel appears willing to sacrifice some performance for
> functionality by building with frame pointers at the drop of a tracing
> hat, userspace is not like that.

Aww, common, Gentoo is brilliant for that :-)

CFLAGS+=-fframe-pointer

emerge -uDNe world

Then again, you'd better not have all that desktop bloat installed,
otherwise that will take ages.. KDE/OOo compile times anyone?

/me runs