Subject: Re: linux-next: powerpc build failure

From: Ingo Molnar <[email-masked]>
Date: Thu, 12 Jun 2008 09:16:12 +0200

* Stephen Rothwell <[email-masked]> wrote:

> > It is, but you need to pass --relax to enable generation of the 
> > trampolines.
> 
> So I tried this (added --relax to LDFLAGS_vmlinux if CONFIG FTRACE was 
> set) and got this;
> 
> /usr/bin/ld: --relax and -r may not be used together
> 
> So, I will disable FTRACE on powerpc for now by removing HAVE_FTRACE 
> from being selected in arch/powerpc/Kconfig.

ugh, please do that hack only privately in your allyesconfig testing and 
do not commit that change to linux-next!

It's not an ftrace bug, this problem is a limitation/bug of the powerpc 
architecture and it appears to me that any kernel feature that brings 
the allyesconfig text size above 32MB on powerpc will trigger this build 
failure.

A few months ago arch/x86 triggered an allyesconfig text size limitation 
at 40MB image size (on 64-bit) and we fixed it instead of disabling the 
feature/driver that happened to bring the image size above 40MB. See 
these commits:

 -------->
 commit 88f3aec7afd9ae3e6f6d221801996b69aad1e3a4
 Author: Ingo Molnar <[email-masked]>
 Date:   Thu Feb 21 11:04:11 2008 +0100

    x86: fix spontaneous reboot with allyesconfig bzImage

 commit 85eb69a16aab5a394ce043c2131319eae35e6493
 Author: Ingo Molnar <[email-masked]>
 Date:   Thu Feb 21 12:50:51 2008 +0100

    x86: increase the kernel text limit to 512 MB
 <--------

	Ingo