On reboot sometimes "sched: Unexpected reschedule of offline CPU#1!"

[Andy Shevchenko]

I have an Intel Merrifield platform where from time to time (don't
know how to reproduce reliably) I have got a warning on reboot.

Requesting system reboot
[   64.945973] reboot: Restarting system
[   64.950770] reboot: machine restart
[   64.955962] ------------[ cut here ]------------
[   64.962601] sched: Unexpected reschedule of offline CPU#1!
[   64.970144] WARNING: CPU: 0 PID: 22 at arch/x86/kernel/smp.c:128
native_smp_send_reschedule+0x2f/0x40
[   64.982429] Modules linked in: brcmfmac brcmutil mmc_block
spi_pxa2xx_platform pwm_lpss_pci pwm_lpss spi_pxa2xx
_pci sdhci_pci cqhci sdhci led_class intel_mrfld_pwrbtn
intel_mrfld_adc extcon_intel_mrfld mmc_core mi0283qt mipi_
dbi tinydrm backlight edt_ft5x06 ti_ads7950
industrialio_triggered_buffer kfifo_buf intel_soc_pmic_mrfld hci_uart
btbcm
[   65.021950] CPU: 0 PID: 22 Comm: kworker/0:1 Tainted: G        W
     5.0.0+ #271
[   65.032718] Hardware name: Intel Corporation Merrifield/BODEGA BAY,
BIOS 542 2015.01.21:18.19.48
[   65.044541] Workqueue:            (null) (events)
[   65.051259] RIP: 0010:native_smp_send_reschedule+0x2f/0x40
[   65.058759] Code: 05 36 dc 53 01 73 15 48 8b 05 8d 30 2c 01 be fd
00 00 00 48 8b 40 30 e9 1f 33 dc 00 89 fe 48
c7 c7 b0 fd e1 ac e8 18 4e 02 00 <0f> 0b c3 66 66 2e 0f 1f 84 00 00 00
00 00 0f 1f 00 48 83 ec 10 48
[   65.083627] RSP: 0000:ffff90f2fe003ed8 EFLAGS: 00010086
[   65.090893] RAX: 0000000000000000 RBX: ffff90f2fdeba4c0 RCX: ffffffffad04cf98
[   65.100085] RDX: 0000000000000001 RSI: 0000000000000096 RDI: ffffffffad71308c
[   65.109278] RBP: 0000000000000000 R08: 00000000000003af R09: 00000000ad55ad55
[   65.118471] R10: 0000000000000000 R11: 0000000000000002 R12: ffff9aaec024bd98
[   65.127661] R13: ffff90f2fe01ba00 R14: ffffffffabce3a30 R15: ffff90f2fe01bb38
[   65.136860] FS:  0000000000000000(0000) GS:ffff90f2fe000000(0000)
knlGS:0000000000000000
[   65.148010] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   65.155823] CR2: 00000000000000b0 CR3: 00000000070c6000 CR4: 00000000001006f0
[   65.165031] Call Trace:
[   65.168522]  <IRQ>
[   65.171574]  update_process_times+0x4a/0x60
[   65.177800]  tick_sched_handle+0x34/0x40
[   65.183751]  tick_sched_timer+0x32/0x70
[   65.189615]  __hrtimer_run_queues+0xfb/0x280
[   65.195911]  hrtimer_interrupt+0xfb/0x210
[   65.201931]  smp_apic_timer_interrupt+0x5d/0x130
[   65.208553]  apic_timer_interrupt+0xf/0x20
[   65.214632]  </IRQ>
[   65.217722] RIP: 0010:finish_task_switch+0x69/0x210
[   65.224553] Code: 00 00 00 00 4d 8b 7d 10 65 4c 8b 34 25 40 4d 01
00 0f 1f 44 00 00 0f 1f 44 00 00 41 c7 45 38
00 00 00 00 c6 03 00 fb 4d 85 e4 <74> 1c 41 8b 84 24 78 03 00 00 a8 20
0f 85 0b 01 00 00 f0 41 ff 4c
[   65.249209] RSP: 0000:ffff9aaec024be48 EFLAGS: 00000246 ORIG_RAX:
ffffffffffffff13
[   65.259706] RAX: 0000000080000000 RBX: ffff90f2fe020900 RCX: 0000000000000000
[   65.268817] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff90f2fcd7e200
[   65.277949] RBP: ffff9aaec024be70 R08: 00000000000000cf R09: ffff90f2fdeba540
[   65.287090] R10: 0000000000000001 R11: 0000000000000006 R12: 0000000000000000
[   65.296238] R13: ffff90f2fcd7e200 R14: ffff90f2fdeba4c0 R15: 0000000000000000
[   65.305401]  __schedule+0x2c9/0x6b0
[   65.309916]  ? _cond_resched+0x10/0x20
[   65.315665]  schedule+0x23/0x70
[   65.319825]  worker_thread+0xa4/0x3c0
[   65.324502]  ? process_one_work+0x3f0/0x3f0
[   65.330650]  kthread+0x10d/0x130
[   65.334891]  ? kthread_create_on_node+0x60/0x60
[   65.341415]  ret_from_fork+0x35/0x40
[   65.345995] ---[ end trace 350a4f4eb4973887 ]---

Any ideas where to look / what possible a root cause?

-- 
With Best Regards,
Andy Shevchenko