After experiencing the issue on the guest, I turned on SMT again and the threads look fine:
$ sudo ppc64_cpu --smt=8 $ sudo ppc64_cpu --info Core 0: 0* 1* 2* 3* 4* 5* 6* 7* Core 1: 8* 9* 10* 11* 12* 13* 14* 15* Core 2: 16* 17* 18* 19* 20* 21* 22* 23* Core 3: 24* 25* 26* 27* 28* 29* 30* 31* Core 4: 32* 33* 34* 35* 36* 37* 38* 39* Core 5: 40* 41* 42* 43* 44* 45* 46* 47* Core 6: 48* 49* 50* 51* 52* 53* 54* 55* Core 7: 56* 57* 58* 59* 60* 61* 62* 63* Core 8: 64* 65* 66* 67* 68* 69* 70* 71* Core 9: 72* 73* 74* 75* 76* 77* 78* 79* Core 10: 80* 81* 82* 83* 84* 85* 86* 87* Core 11: 88* 89* 90* 91* 92* 93* 94* 95* Core 12: 96* 97* 98* 99* 100* 101* 102* 103* Core 13: 104* 105* 106* 107* 108* 109* 110* 111* Core 14: 112* 113* 114* 115* 116* 117* 118* 119* Core 15: 120* 121* 122* 123* 124* 125* 126* 127* Core 16: 128* 129* 130* 131* 132* 133* 134* 135* Core 17: 136* 137* 138* 139* 140* 141* 142* 143* Core 18: 144* 145* 146* 147* 148* 149* 150* 151* Core 19: 152* 153* 154* 155* 156* 157* 158* 159* -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1733864 Title: kernel 4.10.0-40 is hanging with a CPU soft lock Status in The Ubuntu-power-systems project: In Progress Status in linux package in Ubuntu: In Progress Bug description: Kernel 4.10.0-40-generic is causing CPU hung on POWER machines. I got this problem on a POWER8 KVM virtual machine [ 1912.003255] NMI watchdog: BUG: soft lockup - CPU#12 stuck for 24s! [dpkg-deb:31284] [ 1912.004496] Modules linked in: ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs ipt_REJECT nf_reject_ipv4 xfrm_user xfrm_algo xt_addrtype xt_conntrack br_netfilter ebtable_filter ebtables ip6table_filter ip6_tables ib_srpt dm_thin_pool dm_persistent_data dm_bio_prison dm_bufio tcm_qla2xxx qla2xxx vhost_scsi vhost usb_f_tcm tcm_usb_gadget libcomposite udc_core tcm_fc libfc scsi_transport_fc tcm_loop iscsi_target_mod target_core_file target_core_iblock target_core_pscsi target_core_mod ipmi_devintf ipmi_msghandler xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat xt_tcpudp iptable_filter ip_tables x_tables openvswitch nf_conntrack_ipv6 nf_nat_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_defrag_ipv6 nf_nat nf_conntrack binfmt_misc zfs(PO) zunicode(PO) zavl(PO) zcommon(PO) [ 1912.004575] znvpair(PO) spl(O) bridge 8021q garp mrp stp llc vmx_crypto kvm ib_iser rdma_cm iw_cm ib_cm ib_core configfs 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 ibmvscsi ibmveth crc32c_vpmsum virtio_blk [ 1912.004624] CPU: 12 PID: 31284 Comm: dpkg-deb Tainted: P O 4.10.0-40-generic #44~16.04.1-Ubuntu [ 1912.004626] task: c000000775551e00 task.stack: c0000007755ac000 [ 1912.004627] NIP: 00003fff86b71960 LR: 00003fff86b7319c CTR: 000000000000002d [ 1912.004628] REGS: c0000007755afea0 TRAP: 0901 Tainted: P O (4.10.0-40-generic) [ 1912.004629] MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> [ 1912.004635] CR: 42004442 XER: 20000000 [ 1912.004636] CFAR: 00003fff86b719b4 SOFTE: 1 GPR00: 00000000000000a4 00003fffd53f7d70 00003fff86ba5008 0000000000000040 GPR04: 00000000038a20fc 00003fff86467d4b 00000000036c0ed8 000000000000002a GPR08: 00003fff81c41010 00000000000a20f5 0000000000800001 ffffffffffec0ed1 GPR12: 00000000000000a6 00003fff86c8db30 [ 1912.004646] NIP [00003fff86b71960] 0x3fff86b71960 [ 1912.004647] LR [00003fff86b7319c] 0x3fff86b7319c [ 1912.004647] Call Trace: To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1733864/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
