Comment 18 for bug 1733662

That one failed (the script stopped running after taking CPU 9 offline) with the following dmesg output:

[ 119.360953] ------------[ cut here ]------------
[ 119.360955] kernel BUG at /home/jsalisbury/bugs/lp1734327/ac8f82a-revert-test/ubuntu-artful/mm/slub.c:3878!
[ 119.361405] invalid opcode: 0000 [#1] SMP
[ 119.361586] Modules linked in: nls_iso8859_1 kvm_intel kvm irqbypass joydev input_leds ipmi_ssif ipmi_si ipmi_devintf ipmi_msghandler acpi_pad ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel hid_generic pcbc igb usbhid dca aesni_intel hid aes_x86_64 crypto_simd glue_helper ptp cryptd ahci pps_core libahci i2c_algo_bit megaraid_sas
[ 119.363826] CPU: 9 PID: 63 Comm: cpuhp/9 Not tainted 4.13.0-19-generic #22~lp1731031TwoReverts
[ 119.364209] Hardware name: Cisco Systems Inc UCSC-C240-M4L/UCSC-C240-M4L, BIOS C240M4.2.0.10c.0.032320160820 03/23/2016
[ 119.364687] task: ffff98cff8b49740 task.stack: ffffb3274c7b8000
[ 119.364973] RIP: 0010:kfree+0x11c/0x160
[ 119.365133] RSP: 0018:ffffb3274c7bbd60 EFLAGS: 00010246
[ 119.365356] RAX: fffff57a3bff0020 RBX: ffff98cf00000000 RCX: 0000000000000490
[ 119.365663] RDX: 0000000000000000 RSI: ffff98cfff25f4a0 RDI: 0000676f80000000
[ 119.365964] RBP: ffffb3274c7bbd78 R08: 000000000001f4a0 R09: ffffffffbb5dcf6a
[ 119.366262] R10: fffff57a3c000000 R11: 0000000000000000 R12: ffffffffbbf98e60
[ 119.366552] R13: ffffffffbb1dd820 R14: 0000000000000009 R15: 0000000000000001
[ 119.366844] FS: 0000000000000000(0000) GS:ffff98cfff240000(0000) knlGS:0000000000000000
[ 119.367176] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 119.367412] CR2: 000055cc84772018 CR3: 0000000e48e09000 CR4: 00000000001406e0
[ 119.367706] Call Trace:
[ 119.367824] kfree_const+0x20/0x30
[ 119.367975] kobject_put+0x91/0x1a0
[ 119.368134] device_unregister+0x28/0x60
[ 119.368311] cpu_cache_sysfs_exit+0x5a/0xc0
[ 119.368486] ? free_cache_attributes.part.7+0x110/0x110
[ 119.368709] cacheinfo_cpu_pre_down+0x48/0x50
[ 119.368897] cpuhp_invoke_callback+0x84/0x3b0
[ 119.369082] cpuhp_down_callbacks+0x42/0x80
[ 119.369253] cpuhp_thread_fun+0x88/0xe0
[ 119.369433] smpboot_thread_fn+0xec/0x160
[ 119.369598] kthread+0x125/0x140
[ 119.369732] ? sort_range+0x30/0x30
[ 119.369882] ? kthread_create_on_node+0x70/0x70
[ 119.370075] ret_from_fork+0x25/0x30
[ 119.370233] Code: 08 49 83 c4 18 48 89 da 4c 89 ee ff d0 49 8b 04 24 48 85 c0 75 e6 e9 0e ff ff ff 49 8b 02 f6 c4 80 75 0a 49 8b 42 20 a8 01 75 02 <0f> 0b 49 8b 02 31 f6 f6 c4 80 74 04 41 8b 72 6c 4c 89 d7 e8 1c
[ 119.371052] RIP: kfree+0x11c/0x160 RSP: ffffb3274c7bbd60
[ 119.371313] ---[ end trace edef5d0868ec0d2a ]---

The system continued to run, and I was able to issue other commands (ifconfig, efibootmgr), but I rebooted just to be safe.