FYI, we noticed the following commit:

https://github.com/0day-ci/linux Ding-Tianhong/rcu-fix-the-OOM-problem-of-huge-IP-abnormal-packet-traffic/20161118-204521
commit 83ee00c6cf5eaa85f74094d6800732edf7114ef9 ("rcu: fix the OOM problem of huge IP abnormal packet traffic")

in testcase: boot

on test machine: qemu-system-x86_64 -enable-kvm -m 320M

caused below changes:


+------------------------------------------------+------------+------------+
|                                                | 68ad1194cf | 83ee00c6cf |
+------------------------------------------------+------------+------------+
| boot_successes                                 | 6          | 0          |
| boot_failures                                  | 0          | 6          |
| WARNING:at_kernel/softirq.c:#__local_bh_enable | 0          | 6          |
| calltrace:_local_bh_enable                     | 0          | 6          |
+------------------------------------------------+------------+------------+



[    0.846125] PCI: CLS 0 bytes, default 64
[    0.847479] Unpacking initramfs...
[    0.849690] ------------[ cut here ]------------
[    0.850615] WARNING: CPU: 0 PID: 9 at kernel/softirq.c:140 __local_bh_enable+0x35/0x41
[    0.852518] Modules linked in:
[    0.853178] CPU: 0 PID: 9 Comm: rcuos/0 Not tainted 4.9.0-rc1-00041-g83ee00c #1
[    0.854630] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[    0.856628]  ffff8800002f7c70 ffffffff81267760 0000000000000000 ffffffff81837340
[    0.858185]  ffff8800002f7cb0 ffffffff81060e07 0000008c00000009 0000000000000200
[    0.859742]  ffff8800002f7dc8 ffff88000f808bb0 0000000000000001 ffff88000f808bb0
[    0.861293] Call Trace:
[    0.861795]  [<ffffffff81267760>] dump_stack+0x61/0x7e
[    0.862809]  [<ffffffff81060e07>] __warn+0xf5/0x110
[    0.863870]  [<ffffffff81060f85>] warn_slowpath_null+0x18/0x1a
[    0.865020]  [<ffffffff81066b09>] __local_bh_enable+0x35/0x41
[    0.866143]  [<ffffffff81066b52>] _local_bh_enable+0x3d/0x3f
[    0.867252]  [<ffffffff810dbf14>] rcu_nocb_kthread+0x69b/0x6f2
[    0.868393]  [<ffffffff811cbe81>] ? __d_free_external+0x3f/0x3f
[    0.869554]  [<ffffffff810db879>] ? note_gp_changes+0xcd/0xcd
[    0.870679]  [<ffffffff815ff413>] ? __schedule+0x5fc/0x73c
[    0.871755]  [<ffffffff810db879>] ? note_gp_changes+0xcd/0xcd
[    0.872980]  [<ffffffff810898c7>] kthread+0x191/0x1a0
[    0.873971]  [<ffffffff81089736>] ? kthread_park+0x5d/0x5d
[    0.875059]  [<ffffffff8108fd54>] ? finish_task_switch+0x1e4/0x2a0
[    0.876262]  [<ffffffff81089736>] ? kthread_park+0x5d/0x5d
[    0.877331]  [<ffffffff81089736>] ? kthread_park+0x5d/0x5d
[    0.878401]  [<ffffffff81606a45>] ret_from_fork+0x25/0x30
[    0.879484] ---[ end trace 825c5dbf85ebfadd ]---
[    0.899723] workqueue: round-robin CPU selection forced, expect performance impact
[    2.115863] Freeing initrd memory: 9088K (ffff880013700000 - ffff880013fe0000)


To reproduce:

        git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
Xiaolong