Hi Paul,

After merging the rcu tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:

In file included from arch/arm/kernel/asm-offsets.c:14:0:
include/linux/sched.h: In function 'membarrier_sched_out':
include/linux/sched.h:1680:3: error: implicit declaration of function 'sync_core' [-Werror=implicit-function-declaration]
   sync_core();
   ^

Caused by commit

  0d6eb99818da ("membarrier: Provide register sync core cmd")

I have used the rcu tree from next-20170825 for today.

-- 
Cheers,
Stephen Rothwell