FYI, we noticed the following commit:

commit: fbc14616f483788afabe77d05bfb99883dc66c73 ("printk: enable printk offloading")
url: https://github.com/0day-ci/linux/commits/Sergey-Senozhatsky/printk-introduce-printing-kernel-thread/20170330-185752


in testcase: trinity
with following parameters:

	runtime: 300s

test-description: Trinity is a linux system call fuzz tester.
test-url: http://codemonkey.org.uk/projects/trinity/


on test machine: qemu-system-x86_64 -enable-kvm -cpu Westmere -m 512M

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


+-------------------------------------------------+------------+------------+
|                                                 | fd8b6b120c | fbc14616f4 |
+-------------------------------------------------+------------+------------+
| boot_successes                                  | 8          | 8          |
| boot_failures                                   | 0          | 6          |
| BUG:kernel_reboot-without-warning_in_test_stage | 0          | 4          |
| BUG:kernel_hang_in_test_stage                   | 0          | 2          |
+-------------------------------------------------+------------+------------+



[   21.009531] VFS: Warning: trinity-c2 using old stat() call. Recompile your binary.
[   21.148898] VFS: Warning: trinity-c0 using old stat() call. Recompile your binary.
[   22.298208] warning: process `trinity-c2' used the deprecated sysctl system call with 

Elapsed time: 310
BUG: kernel reboot-without-warning in test stage

initrds=(
	/osimage/yocto/yocto-tiny-i386-2016-04-22.cgz
	/lkp/scheduled/vm-kbuild-yocto-ia32-9/trinity-300s-yocto-tiny-i386-2016-04-22.cgz-fbc14616f483788afabe77d05bfb99883dc66c73-20170331-102676-cxuzks-0.cgz
	/lkp/lkp/lkp-i386.cgz


To reproduce:

        git clone https://github.com/01org/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
Kernel Test Robot