Comment 15 for bug 1777194

------- Comment From <email address hidden> 2018-07-20 02:36 EDT-------
Following lockups are observed

Jul 20 01:15:35 lep8d kernel: [ 483.899693] Watchdog CPU:126 Hard LOCKUP
Jul 20 01:15:35 lep8d kernel: [ 483.899700] Modules linked in: serpent_generic cuse twofish_generic twofish_common vhost_net tap vhost_vsock vmw_vsock_virtio_transport_common vhost vsock lrw algif_skcipher tgr192 unix_diag wp512 sctp rmd320 rmd256 snd_seq snd_seq_device snd_timer rmd160 snd soundcore rmd128 dccp_ipv4 md4 dccp algif_hash af_alg xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc devlink ip6table_filter ip6_tables iptable_filter uio_pdrv_genirq uio kvm_hv kvm leds_powernv powernv_rng vmx_crypto ipmi_powernv ipmi_devintf ibmpowernv ipmi_msghandler binfmt_misc sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables
Jul 20 01:15:35 lep8d kernel: [ 483.900118] x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear uas usb_storage crct10dif_vpmsum crc32c_vpmsum ipr tg3 [last unloaded: ebtables]
Jul 20 01:15:35 lep8d kernel: [ 483.900292] CPU: 126 PID: 70582 Comm: stress-ng-fstat Not tainted 4.15.0-29-generic #32~lp1777194
Jul 20 01:15:35 lep8d kernel: [ 483.900300] NIP: c000000000d02364 LR: c0000000001145ac CTR: c000000000162300
Jul 20 01:15:35 lep8d kernel: [ 483.900305] REGS: c00000003fa17d80 TRAP: 0900 Not tainted (4.15.0-29-generic)
Jul 20 01:15:35 lep8d kernel: [ 483.900312] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 22004244 XER: 00000000
Jul 20 01:15:35 lep8d kernel: [ 483.900360] CFAR: c000000000d0236c SOFTE: 0
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR00: c0000000001145ac c000000fa8147d20 c0000000016eaf00 c000000001712180
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR04: 000000000000000d 0000000000000040 0000000000000000 0000000000000842
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR08: 0000002ffbad0000 0000000000000000 000000008000007e c000000fa81bc830
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR12: 0000000000004400 c00000000fad6a00 0000026380759318 000074efb46d0000
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR16: 0000026380759210 000074efbae24410 000074efbae24420 000074efb4edf240
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR20: 0000000000000000 00007fffe93cbe40 00007fffe93cbe78 0000000000000000
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR24: c000000fa81bc780 0000000000000000 0000000000000000 c000000001712180
Jul 20 01:15:35 lep8d kernel: [ 483.900360] GPR28: c000002d55ace160 c000000fa8147db0 0000000000000000 c000000001712180
Jul 20 01:15:35 lep8d kernel: [ 483.900551] NIP [c000000000d02364] _raw_write_lock_irq+0x74/0xe0
Jul 20 01:15:35 lep8d kernel: [ 483.900557] LR [c0000000001145ac] do_exit+0x41c/0xc80
Jul 20 01:15:35 lep8d kernel: [ 483.900565] Call Trace:
Jul 20 01:15:35 lep8d kernel: [ 483.900574] [c000000fa8147d20] [c000000fa8147d50] 0xc000000fa8147d50 (unreliable)
Jul 20 01:15:35 lep8d kernel: [ 483.900590] [c000000fa8147d50] [c000000000114590] do_exit+0x400/0xc80
Jul 20 01:15:35 lep8d kernel: [ 483.900619] [c000000fa8147e10] [c000000000114e74] SyS_exit+0x24/0x30
Jul 20 01:15:35 lep8d kernel: [ 483.900632] [c000000fa8147e30] [c00000000000b284] system_call+0x58/0x6c
Jul 20 01:15:35 lep8d kernel: [ 483.900641] Instruction dump:
Jul 20 01:15:35 lep8d kernel: [ 483.900648] 2fa90000 409e0018 38210030 ebe1fff8 4e800020 60000000 60420000 7c210b78
Jul 20 01:15:35 lep8d kernel: [ 483.900692] e92d0000 89290009 71290002 40820050 <813f0000> 2f890000 409effe4 7c421378

Jul 20 01:15:35 lep8d kernel: [ 483.975703] Watchdog CPU:142 Hard LOCKUP
Jul 20 01:15:35 lep8d kernel: [ 483.975723] Modules linked in: serpent_generic cuse twofish_generic twofish_common vhost_net tap vhost_vsock vmw_vsock_virtio_transport_common vhost vsock lrw algif_skcipher tgr192 unix_diag wp512 sctp rmd320 rmd256 snd_seq snd_seq_device snd_timer rmd160 snd soundcore rmd128 dccp_ipv4 md4 dccp algif_hash af_alg xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp bridge stp llc devlink ip6table_filter ip6_tables iptable_filter uio_pdrv_genirq uio kvm_hv kvm leds_powernv powernv_rng vmx_crypto ipmi_powernv ipmi_devintf ibmpowernv ipmi_msghandler binfmt_misc sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables
Jul 20 01:15:35 lep8d kernel: [ 483.976470] x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear uas usb_storage crct10dif_vpmsum crc32c_vpmsum ipr tg3 [last unloaded: ebtables]
Jul 20 01:15:35 lep8d kernel: [ 483.976759] CPU: 142 PID: 61106 Comm: stress-ng-sigpi Not tainted 4.15.0-29-generic #32~lp1777194
Jul 20 01:15:35 lep8d kernel: [ 483.976771] NIP: c000000000d02354 LR: c00000000011287c CTR: 0000000000000000
Jul 20 01:15:35 lep8d kernel: [ 483.976787] REGS: c00000003f957d80 TRAP: 0900 Not tainted (4.15.0-29-generic)
Jul 20 01:15:35 lep8d kernel: [ 483.976798] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 24002244 XER: 20000000
Jul 20 01:15:35 lep8d kernel: [ 483.976926] CFAR: c000000000d0236c SOFTE: 0
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR00: c00000000011287c c000002d52dbfb30 c0000000016eaf00 c000000001712180
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR04: 000000000000000d c000000000fa82d0 0000000000011395 ffffff0000000000
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR08: 61c8864680b583eb 0000000000000006 000000008000008e 000000001b8a8bbc
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR12: 0000000024002248 c00000000fae1a00 0000000000000000 0000000000000000
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR16: 00000000000186a0 00007fffe93ccfb0 0000026367e470a0 00007fffe93ccfa8
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR20: 0000026367e470a8 0000000000000010 0000000000000000 00007fffe93cd26a
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR24: c000000000112480 0000000000000000 c000000001712180 c0000000018b1c88
Jul 20 01:15:35 lep8d kernel: [ 483.976926] GPR28: 5deadbeef0000200 0000000000000000 c000002d52dbfcf0 c000000001712180
Jul 20 01:15:35 lep8d kernel: [ 483.977433] NIP [c000000000d02354] _raw_write_lock_irq+0x64/0xe0
Jul 20 01:15:35 lep8d kernel: [ 483.977441] LR [c00000000011287c] release_task+0xcc/0x590
Jul 20 01:15:35 lep8d kernel: [ 483.977456] Call Trace:
Jul 20 01:15:35 lep8d kernel: [ 483.977468] [c000002d52dbfb30] [5deadbeef0000200] 0x5deadbeef0000200 (unreliable)
Jul 20 01:15:35 lep8d kernel: [ 483.977489] [c000002d52dbfb60] [c000000000112870] release_task+0xc0/0x590
Jul 20 01:15:35 lep8d kernel: [ 483.977522] [c000002d52dbfbf0] [c000000000113780] wait_consider_task+0xa40/0xbe0
Jul 20 01:15:35 lep8d kernel: [ 483.977538] [c000002d52dbfc60] [c000000000113ab0] do_wait+0x190/0x2e0
Jul 20 01:15:35 lep8d kernel: [ 483.977557] [c000002d52dbfcd0] [c000000000115240] kernel_wait4+0xa0/0x1a0
Jul 20 01:15:35 lep8d kernel: [ 483.977572] [c000002d52dbfd70] [c0000000001153a4] SyS_wait4+0x64/0xc0
Jul 20 01:15:35 lep8d kernel: [ 483.977586] [c000002d52dbfe30] [c00000000000b284] system_call+0x58/0x6c
Jul 20 01:15:35 lep8d kernel: [ 483.977596] Instruction dump:
Jul 20 01:15:35 lep8d kernel: [ 483.977620] 40c20010 7d40192d 40c2fff0 7c2004ac 2fa90000 409e0018 38210030 ebe1fff8
Jul 20 01:15:35 lep8d kernel: [ 483.977708] 4e800020 60000000 60420000 7c210b78 <e92d0000> 89290009 71290002 40820050

Attaching syslog here.