On 11/28/2016 6:33 AM, Sebastian Andrzej Siewior wrote:

On 2016-11-21 16:30:40 [+0800], He Zhe wrote:

quoted

And I've tried on "a7fac75 Linux 4.8.1" and the latest linux-4.8.y-rt-rebase branch.They have the same issue.

It works here. I tried your config with oldconfig on a x86-64 box. Do
you have a x86-64 config?

Hi Sebastian,

Thanks for following up. I had been distracted by something else. And, I 
did more testing, then I narrowed it down to ARM and PPC only.

In addition, I narrowed it down to CONFIG_DEBUG_PREEMPT. function_graph 
tracer works well with it disabled on ARM and PPC. But, I haven't got 
time to figure out why.

Yang

quoted

Zhe

Sebastian