Re: ftrace: fix depends

[Heiko Carstens <heiko.carstens@de.ibm.com>]

On Tue, Oct 28, 2008 at 06:02:41PM +0000, Linux Kernel Mailing List wrote:
> Gitweb:     http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c2db8054c1eaf99983d8deee347876b01c26c2cf
> Commit:     c2db8054c1eaf99983d8deee347876b01c26c2cf
> Parent:     bd95b88d9e51fcbf392a7e90338a8fcc3499cbd6
> Author:     Steven Rostedt <rostedt@goodmis.org>
> AuthorDate: Mon Oct 6 19:06:11 2008 -0400
> Committer:  Ingo Molnar <mingo@elte.hu>
> CommitDate: Mon Oct 20 18:27:02 2008 +0200
> 
>     ftrace: fix depends
>     
>     A lot of tracers have HAVE_FTRACE as a dependent config where it
>     really should not. The HAVE_FTRACE is a misnomer (soon to be fixed)
>     and describes if the architecture has the function tracer (mcount)
>     implemented. The ftrace infrastructure is implemented in all archs.
>     
>     Signed-off-by: Steven Rostedt <srostedt@redhat.com>
>     Signed-off-by: Ingo Molnar <mingo@elte.hu>

Hmm... this is not very true. I count three architectures which have this
implemented plus arm with a 'depends on' plus sh with the broken HAVE_FTRACE
instead of HAVE_FUNCTION_TRACER.

All other architectures will see something like this:

kernel/built-in.o: In function `tracer_alloc_buffers':
trace.c:(.init.text+0x42c2): undefined reference to `nop_trace'
trace.c:(.init.text+0x42ec): undefined reference to `nop_trace'
make: *** [.tmp_vmlinux1] Error 1