I'm afraid that one fails, too, on the second run when bringing CPU10 back online. Here's the dmesg output: [ 154.987312] smpboot: Booting Node 1 Processor 10 APIC 0x14 [ 154.992953] BUG: unable to handle kernel paging request at 0000317865646e69 [ 154.993932] IP: __kmalloc_track_caller+0x97/0x1f0 [ 154.994847] PGD 0 [ 154.994848] P4D 0 [ 154.997397] Oops: 0000 [#1] SMP [ 154.998250] Modules linked in: nls_iso8859_1 intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm joydev input_leds ipmi_ssif irqbypass mac_hid ipmi_si shpchp intel_cstate intel_rapl_perf acpi_power_meter ipmi_devintf acpi_pad mei_me lpc_ich ipmi_msghandler mei 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 ses enclosure scsi_transport_sas mgag200 ttm fnic hid_generic crct10dif_pclmul crc32_pclmul ghash_clmulni_intel drm_kms_helper pcbc usbhid syscopyarea igb sysfillrect libfcoe aesni_intel sysimgblt dca fb_sys_fops i2c_algo_bit aes_x86_64 hid crypto_simd glue_helper libfc ptp mxm_wmi ahci drm cryptd [ 155.005714] libahci pps_core scsi_transport_fc enic megaraid_sas wmi [ 155.006913] CPU: 10 PID: 69 Comm: cpuhp/10 Not tainted 4.13.0-13-generic #14~lp1733662Commitac2fc5adab0f4 [ 155.008154] Hardware name: Cisco Systems Inc UCSC-C240-M4L/UCSC-C240-M4L, BIOS C240M4.2.0.10c.0.032320160820 03/23/2016 [ 155.009427] task: ffff91c7b8785d00 task.stack: ffffa8760c7e8000 [ 155.010718] RIP: 0010:__kmalloc_track_caller+0x97/0x1f0 [ 155.012014] RSP: 0000:ffffa8760c7ebc48 EFLAGS: 00010206 [ 155.013308] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000014b9 [ 155.014618] RDX: 00000000000014b8 RSI: 0000000000000000 RDI: 000000000001f3e0 [ 155.015946] RBP: ffffa8760c7ebc80 R08: ffff91c7bf29f3e0 R09: ffff91a7bf807c00 [ 155.017284] R10: ffffa8760c7ebce0 R11: 0000000000000006 R12: 0000317865646e69 [ 155.018620] R13: 00000000014000c0 R14: 0000000000000007 R15: ffff91a7bf807c00 [ 155.019965] FS: 0000000000000000(0000) GS:ffff91c7bf280000(0000) knlGS:0000000000000000 [ 155.021329] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 155.022710] CR2: 0000317865646e69 CR3: 0000000ec6c09000 CR4: 00000000001406e0 [ 155.024101] Call Trace: [ 155.025490] ? kvasprintf_const+0x45/0xa0 [ 155.026906] kvasprintf+0x66/0xd0 [ 155.028304] kvasprintf_const+0x45/0xa0 [ 155.029703] kobject_set_name_vargs+0x23/0x90 [ 155.031101] cpu_device_create+0xa4/0x100 [ 155.032485] ? smp_call_function_single+0xb9/0xe0 [ 155.033891] cacheinfo_cpu_online+0x2ac/0x400 [ 155.035295] ? get_cpu_cacheinfo+0x50/0x50 [ 155.036709] cpuhp_invoke_callback+0x84/0x3b0 [ 155.038101] cpuhp_up_callbacks+0x36/0xc0 [ 155.039513] cpuhp_thread_fun+0xd4/0xe0 [ 155.040923] smpboot_thread_fn+0xec/0x160 [ 155.042319] kthread+0x125/0x140 [ 155.043706] ? sort_range+0x30/0x30 [ 155.045107] ? kthread_create_on_node+0x70/0x70 [ 155.046515] ret_from_fork+0x25/0x30 [ 155.047906] Code: 08 65 4c 03 05 ab e5 7d 5b 49 83 78 10 00 4d 8b 20 0f 84 ef 00 00 00 4d 85 e4 0f 84 e6 00 00 00 49 63 41 20 49 8b 39 48 8d 4a 01 <49> 8b 1c 04 4c 89 e0 65 48 0f c7 0f 0f 94 c0 84 c0 74 bb 49 63 [ 155.050922] RIP: __kmalloc_track_caller+0x97/0x1f0 RSP: ffffa8760c7ebc48 [ 155.052426] CR2: 0000317865646e69 [ 155.053914] ---[ end trace f7bb4aa3c197a453 ]--- To be sure, here's the kernel version information: $ uname -a Linux oil-boldore 4.13.0-13-generic #14~lp1733662Commitac2fc5adab0f4 SMP Fri Jan 5 15:31:13 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux