Hi Steven,

After merging the ftrace tree, today's linux-next build (powerpc
allnoconfig) failed like this:

In file included from include/asm-generic/percpu.h:6:0,
                 from arch/powerpc/include/asm/percpu.h:19,
                 from include/linux/percpu.h:11,
                 from include/linux/sched.h:41,
                 from arch/powerpc/kernel/asm-offsets.c:17:
include/linux/percpu.h:138:17: error: 'printk_func_t' undeclared here (not in a function)
 DECLARE_PER_CPU(printk_func_t, printk_func);
                 ^
include/linux/percpu-defs.h:101:38: note: in definition of macro 'DECLARE_PER_CPU_SECTION'
  extern __PCPU_ATTRS(sec) __typeof__(type) name
                                      ^
include/linux/percpu.h:138:1: note: in expansion of macro 'DECLARE_PER_CPU'
 DECLARE_PER_CPU(printk_func_t, printk_func);
 ^

Caused by commit afdc34a3d3b8 ("printk: Add per_cpu printk func to
allow printk to be diverted").  See Rule 1 in
Documentation/SubmitChecklist.

I reverted that commit (and the following one (a9edc8809328 "x86/nmi:
Perform a safe NMI stack trace on all CPUs" in case it depended in it)
for today.
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au