Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: af4911517829034538d28c015577eaa335c5e011 ("[PATCH RFC v2] rcu/segcblist: Add counters to segcblist datastructure")
url: https://github.com/0day-ci/linux/commits/Joel-Fernandes-Google/rcu-segcblist-Add-counters-to-segcblist-datastructure/20200719-115700
base: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git 9ebcfadb0610322ac537dd7aa5d9cbc2b2894c68

in testcase: boot

on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

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


+--------------------------------------------+----------+------------+
|                                            | v5.8-rc3 | af49115178 |
+--------------------------------------------+----------+------------+
| boot_successes                             | 354      | 0          |
| boot_failures                              | 0        | 6          |
| WARNING:at_kernel/rcu/tree.c:#rcu_do_batch | 0        | 6          |
| EIP:rcu_do_batch                           | 0        | 6          |
+--------------------------------------------+----------+------------+


If you fix the issue, kindly add following tag
Reported-by: kernel test robot <lkp@intel.com>


[    0.737571] WARNING: CPU: 0 PID: 1 at kernel/rcu/tree.c:2471 rcu_do_batch+0x29e/0x4b0
[    0.737572] Modules linked in:
[    0.737577] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc3-00001-gaf49115178290 #3
[    0.737579] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[    0.737581] EIP: rcu_do_batch+0x29e/0x4b0
[    0.737584] Code: ff ff 8d b4 26 00 00 00 00 8d 76 00 2b 15 b0 d3 9a df 39 c2 7e 06 8b 7d d0 89 47 68 8b 45 d0 8b 40 2c 85 c0 0f 85 ed fe ff ff <0f> 0b e9 e6 fe ff ff 8d 76 00 8b 5d ec 8b 72 14 8b 15 00 d6 9a df
[    0.737586] EAX: 00000000 EBX: ee920eec ECX: 00000001 EDX: ffffd8f0
[    0.737588] ESI: df9ad3c0 EDI: ee920ec0 EBP: ee433f9c ESP: ee433f5c
[    0.737590] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010046
[    0.737596] CR0: 80050033 CR2: ffffffff CR3: 1fb57000 CR4: 000006d0
[    0.737597] Call Trace:
[    0.737600]  <SOFTIRQ>
[    0.737608]  ? run_timer_softirq+0x23a/0x470
[    0.737611]  rcu_core+0xd5/0x250
[    0.737614]  rcu_core_si+0x8/0x10
[    0.737620]  __do_softirq+0xac/0x27b
[    0.737623]  ? __entry_text_end+0x8/0x8
[    0.737627]  call_on_stack+0x40/0x50
[    0.737628]  </SOFTIRQ>
[    0.737632]  ? irq_exit_rcu+0x95/0xa0
[    0.737639]  ? sysvec_apic_timer_interrupt+0x1f/0x30
[    0.737643]  ? screen_glyph_unicode+0x80/0x80
[    0.737645]  ? handle_exception+0x145/0x145
[    0.737647]  ? screen_glyph_unicode+0x80/0x80
[    0.737652]  ? console_unlock+0x3a9/0x550
[    0.737655]  ? sysvec_call_function_single+0x30/0x30
[    0.737657]  ? console_unlock+0x3a9/0x550
[    0.737660]  ? vprintk_emit+0xf6/0x1e0
[    0.737663]  ? vprintk_default+0x12/0x20
[    0.737665]  ? vprintk_func+0x49/0xdd
[    0.737667]  ? printk+0xe/0x10
[    0.737671]  ? do_boot_cpu.cold+0xa/0x93
[    0.737674]  ? native_cpu_up+0xd1/0x130
[    0.737676]  ? _cond_resched+0x12/0x30
[    0.737678]  ? bringup_cpu+0x23/0xb0
[    0.737680]  ? cpus_read_trylock+0x50/0x50
[    0.737682]  ? cpuhp_invoke_callback+0x7b/0x5b0
[    0.737689]  ? init_idle+0x142/0x150
[    0.737694]  ? ring_buffer_record_is_set_on+0x10/0x10
[    0.737696]  ? _cpu_up+0x9d/0x150
[    0.737699]  ? cpu_up+0x7b/0x80
[    0.737701]  ? bringup_nonboot_cpus+0x44/0x60
[    0.737706]  ? smp_init+0x21/0x5a
[    0.737709]  ? kernel_init_freeable+0xa6/0x1ce
[    0.737711]  ? rest_init+0xa1/0xa1
[    0.737713]  ? kernel_init+0x8/0xdf
[    0.737716]  ? ret_from_fork+0x1c/0x28
[    0.737719] ---[ end trace 92c373f816251135 ]---


To reproduce:

        # build kernel
	cd linux
	cp config-5.8.0-rc3-00001-gaf49115178290 .config
	make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 olddefconfig prepare modules_prepare bzImage

        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,
lkp