We saw this in our syslogs recently and was curious to know if this was a known issue.
Apr 13 17:14:42 hv5 kernel: [10485687.112290] huge_memory: mapcount 0 page_mapcount 1
Apr 13 17:14:42 hv5 kernel: [10485687.112315] ------------[ cut here ]------------
Apr 13 17:14:42 hv5 kernel: [10485687.113784] kernel BUG at /build/buildd/linux-lts-utopic-3.16.0/mm/huge_memory.c:1870!
Apr 13 17:14:42 hv5 kernel: [10485687.116270] invalid opcode: 0000 [#1] SMP
Apr 13 17:14:42 hv5 kernel: [10485687.117499] Modules linked in: vhost_net vhost macvtap macvlan cdc_ether usbnet mii mpt3sas mpt2sas raid_class scsi_transport_sas mptctl mptbase ipmi_si ipt_MASQUERADE iptable
_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle xt_tcpudp ip6table_filter ip6_tables iptable_filter ip_tables x_tables dell_rbu joydev x86_p
kg_temp_thermal intel_powerclamp coretemp kvm_intel kvm bridge crct10dif_pclmul stp crc32_pclmul llc ghash_clmulni_intel aesni_intel ipmi_devintf aes_x86_64 lrw dm_multipath dcdbas gf128mul scsi_dh glue_helper abl
k_helper cryptd ipmi_msghandler shpchp wmi lpc_ich mei_me acpi_power_meter mei mac_hid bonding lp parport hid_generic usbhid hid igb i2c_algo_bit dca ahci ptp megaraid_sas libahci pps_core [last unloaded: ipmi_si]
Apr 13 17:14:42 hv5 kernel: [10485687.416032] CPU: 15 PID: 477 Comm: kswapd1 Not tainted 3.16.0-30-generic #40~14.04.1-Ubuntu
Apr 13 17:14:42 hv5 kernel: [10485687.495073] Hardware name: Dell Inc. PowerEdge R630/0CNCJW, BIOS 1.3.6 06/03/2015
Apr 13 17:14:42 hv5 kernel: [10485687.581816] task: ffff882ff72d9e90 ti: ffff8817f6520000 task.ti: ffff8817f6520000
Apr 13 17:14:42 hv5 kernel: [10485687.673496] RIP: 0010:[<ffffffff811c14c9>] [<ffffffff811c14c9>] __split_huge_page+0x6d9/0x720
Apr 13 17:14:42 hv5 kernel: [10485687.771517] RSP: 0018:ffff8817f6523958 EFLAGS: 00010282
Apr 13 17:14:42 hv5 kernel: [10485687.823223] RAX: 0000000000000027 RBX: ffff882ff9b33440 RCX: 0000000000000000
Apr 13 17:14:42 hv5 kernel: [10485687.929779] RDX: ffff88301eceee40 RSI: ffff88301eced418 RDI: 0000000000000246
Apr 13 17:14:42 hv5 kernel: [10485688.040614] RBP: ffff8817f65239e0 R08: 0000000000000096 R09: 00000000000007e6
Apr 13 17:14:42 hv5 kernel: [10485688.155377] R10: 0000000000000000 R11: ffff8817f6523676 R12: 0000000000000000
Apr 13 17:14:42 hv5 kernel: [10485688.271454] R13: 00007f141be00000 R14: ffff8817f5fe1880 R15: ffffea00af208000
Apr 13 17:14:42 hv5 kernel: [10485688.388413] FS: 0000000000000000(0000) GS:ffff88301ece0000(0000) knlGS:0000000000000000
Apr 13 17:14:42 hv5 kernel: [10485688.505955] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Apr 13 17:14:42 hv5 kernel: [10485688.564912] CR2: 00007fad5c045000 CR3: 0000000001c13000 CR4: 00000000001427e0
Apr 13 17:14:42 hv5 kernel: [10485688.679748] Stack:
Apr 13 17:14:42 hv5 kernel: [10485688.735473] ffff882ff6833580 ffff882ff9b33440 ffff8817f65239c0 ffffffff81199f45
Apr 13 17:14:42 hv5 kernel: [10485688.848342] ffff8817f6523bc8 00000000811a2afb 00000007f141b800 00000007f141be00
Apr 13 17:14:42 hv5 kernel: [10485688.959697] ffff882ff70c3b30 00007f141c000000 ffff882ff722d200 ffffea00bfe29c70
Apr 13 17:14:42 hv5 kernel: [10485689.071092] Call Trace:
Apr 13 17:14:42 hv5 kernel: [10485689.125872] [<ffffffff81199f45>] ? rmap_walk+0x265/0x330
Apr 13 17:14:42 hv5 kernel: [10485689.180164] [<ffffffff811c1578>] split_huge_page_to_list+0x68/0xd0
Apr 13 17:14:42 hv5 kernel: [10485689.234080] [<ffffffff8119f8a7>] add_to_swap+0x57/0x80
Apr 13 17:14:42 hv5 kernel: [10485689.286071] [<ffffffff81174148>] shrink_page_list+0x5d8/0xa70
Apr 13 17:14:42 hv5 kernel: [10485689.338145] [<ffffffff81174c75>] shrink_inactive_list+0x1c5/0x560
Apr 13 17:14:42 hv5 kernel: [10485689.389177] [<ffffffff81175973>] shrink_lruvec+0x523/0x710
Apr 13 17:14:42 hv5 kernel: [10485689.439476] [<ffffffff81175bdc>] shrink_zone+0x7c/0x1b0
Apr 13 17:14:42 hv5 kernel: [10485689.489084] [<ffffffff81176d15>] balance_pgdat+0x3b5/0x620
Apr 13 17:14:42 hv5 kernel: [10485689.537806] [<ffffffff811770db>] kswapd+0x15b/0x420
Apr 13 17:14:42 hv5 kernel: [10485689.584677] [<ffffffff810b4cd0>] ? prepare_to_wait_event+0x100/0x100
Apr 13 17:14:42 hv5 kernel: [10485689.631650] [<ffffffff81176f80>] ? balance_pgdat+0x620/0x620
Apr 13 17:14:42 hv5 kernel: [10485689.677100] [<ffffffff810912c2>] kthread+0xd2/0xf0
Apr 13 17:14:42 hv5 kernel: [10485689.720987] [<ffffffff810911f0>] ? kthread_create_on_node+0x1c0/0x1c0
Apr 13 17:14:42 hv5 kernel: [10485689.765352] [<ffffffff8176ac3c>] ret_from_fork+0x7c/0xb0
Apr 13 17:14:42 hv5 kernel: [10485689.808213] [<ffffffff810911f0>] ? kthread_create_on_node+0x1c0/0x1c0
Apr 13 17:14:42 hv5 kernel: [10485689.849267] Code: e1 fe ff 8b 4d a8 e9 3e fa ff ff 0f 0b 0f 0b 0f 0b 0f 0b 41 8b 57 18 8b 75 a4 48 c7 c7 c8 ef a8 81 31 c0 83 c2 01 e8 6b a0 59 00 <0f> 0b 0f 0b 41 8b 4f 18 8b
75 a4 89 c2 48 c7 c7 40 f0 a8 81 31
Apr 13 17:14:42 hv5 kernel: [10485689.974478] RIP [<ffffffff811c14c9>] __split_huge_page+0x6d9/0x720
Apr 13 17:14:42 hv5 kernel: [10485690.015842] RSP <ffff8817f6523958>
Apr 13 17:14:42 hv5 kernel: [10485690.121084] ---[ end trace 56bed1017e8a86b3 ]---