FYI, we noticed the following commit (built with gcc-7):

commit: 2d251ff6e66d7978b3e7a9c69e99b7150de26926 ("mm, oom: fix unnecessary killing of additional processes")
url: https://github.com/0day-ci/linux/commits/David-Rientjes/mm-oom-fix-unnecessary-killing-of-additional-processes/20180527-033815
base: git://git.cmpxchg.org/linux-mmotm.git master

in testcase: boot

on test machine: qemu-system-i386 -enable-kvm -cpu Haswell,+smep,+smap -m 360M

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


+------------------------------------------------------------------+------------+------------+
|                                                                  | 0b018d19da | 2d251ff6e6 |
+------------------------------------------------------------------+------------+------------+
| boot_successes                                                   | 4          | 0          |
| boot_failures                                                    | 4          | 4          |
| invoked_oom-killer:gfp_mask=0x                                   | 4          | 2          |
| Mem-Info                                                         | 4          | 4          |
| Out_of_memory:Kill_process                                       | 4          | 4          |
| Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 4          |            |
| BUG:unable_to_handle_kernel                                      | 0          | 4          |
| Oops:#[##]                                                       | 0          | 4          |
| EIP:oom_reaper                                                   | 0          | 4          |
| Kernel_panic-not_syncing:Fatal_exception                         | 0          | 4          |
+------------------------------------------------------------------+------------+------------+



[   11.063029] BUG: unable to handle kernel NULL pointer dereference at 00000204
[   11.064104] *pde = 00000000 
[   11.064548] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[   11.065328] CPU: 0 PID: 21 Comm: oom_reaper Not tainted 4.17.0-rc5-mm1-00218-g2d251ff #1
[   11.066537] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[   11.067786] EIP: oom_reaper+0x115/0x296
[   11.068374] Code: 01 00 00 bb 54 92 65 7e c7 05 ac a8 65 7e 00 02 00 00 b8 80 a8 65 7e e8 9c a2 63 00 85 db 0f 84 fa fe ff ff 8b 83 ac 04 00 00 <8b> b0 04 02 00 00 8b 86 c8 02 00 00 0f ba e0 15 0f 82 55 01 00 00 
[   11.071210] EAX: 00000000 EBX: 7e659254 ECX: 00000001 EDX: 00000000
[   11.072142] ESI: 78090960 EDI: 7816b500 EBP: 78167f8c ESP: 78167f68
[   11.073073] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010202
[   11.074075] CR0: 80050033 CR2: 00000204 CR3: 033d7000 CR4: 00040690
[   11.074994] Call Trace:
[   11.075380]  ? wait_woken+0x75/0x75
[   11.075911]  ? kthread+0xef/0xf4
[   11.076413]  ? __oom_reap_task_mm+0x6f/0x6f
[   11.077036]  ? kthread_create_on_node+0x1a/0x1a
[   11.077718]  ? ret_from_fork+0x19/0x24
[   11.078286] Modules linked in:
[   11.078747] CR2: 0000000000000204
[   11.079253] ---[ end trace 881b7ebfce401a98 ]---


To reproduce:

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



Thanks,
Xiaolong