Hi Peter,

[auto build test ERROR on tip/sched/core]
[also build test ERROR on v4.9-rc7 next-20161128]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Jacob-Pan/Stop-sched-tick-in-idle-injection-task/20161129-062641
config: i386-randconfig-x007-201648 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

Note: the linux-review/Jacob-Pan/Stop-sched-tick-in-idle-injection-task/20161129-062641 HEAD 84bf4b8c5cda5c3d80df1d46e4e4f7e3f5ad31a6 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   kernel/sched/idle.c: In function 'play_idle':
>> kernel/sched/idle.c:304:2: error: implicit declaration of function 'cpuidle_use_deepest_state' [-Werror=implicit-function-declaration]
     cpuidle_use_deepest_state(true);
     ^~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/cpuidle_use_deepest_state +304 kernel/sched/idle.c

   298		WARN_ON_ONCE(!(current->flags & PF_NO_SETAFFINITY));
   299		WARN_ON_ONCE(!duration_ms);
   300	
   301		rcu_sleep_check();
   302		preempt_disable();
   303		current->flags |= PF_IDLE;
 > 304		cpuidle_use_deepest_state(true);
   305	
   306		it.done = 0;
   307		hrtimer_init_on_stack(&it.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation