Comment 36 for bug 1413540

Hi,

Just wanted to chime in that this bug also affected me - running OpenStack Juno w/KVM inside a KVM hypervisor.

CPU on the host machine is:
vendor_id : GenuineIntel
cpu family : 6
model : 58
model name : Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz

running 14.04 with the latest packages applied as of today (2015-03-27) for both the host and the guest.

Lockup appeared to happen with one host-guest VM after I altered the number of CPUs allocated to another VM (yet to reboot that VM for changes to take affect), though I had also recently booted a new host-guest-guest VM.

ar 27 15:12:43 compute ntpd[1775]: peers refreshed
Mar 27 15:12:43 compute ntpd[1775]: new interface(s) found: waking up resolver
Mar 27 15:12:48 compute dnsmasq-dhcp[2044]: DHCPDISCOVER(br100) fa:16:3e:c3:81:22
Mar 27 15:12:48 compute dnsmasq-dhcp[2044]: DHCPOFFER(br100) 203.0.113.27 fa:16:3e:c3:81:22
Mar 27 15:12:48 compute dnsmasq-dhcp[2044]: DHCPREQUEST(br100) 203.0.113.27 fa:16:3e:c3:81:22
Mar 27 15:12:48 compute dnsmasq-dhcp[2044]: DHCPACK(br100) 203.0.113.27 fa:16:3e:c3:81:22 test03
Mar 27 15:15:40 compute kernel: [ 436.100002] BUG: soft lockup - CPU#5 stuck for 23s! [ksmd:68]
Mar 27 15:15:40 compute kernel: [ 436.100002] Modules linked in: vhost_net vhost macvtap macvlan xt_CHECKSUM ebt_ip ebt_arp ebtable_filter br
idge stp llc xt_conntrack xt_nat xt_tcpudp iptable_mangle iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack ip6tabl
e_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables nbd ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core ib_addr iscsi_
tcp libiscsi_tcp libiscsi scsi_transport_iscsi snd_hda_intel cirrus snd_hda_codec ttm snd_hwdep drm_kms_helper snd_pcm drm snd_page_alloc snd_
timer syscopyarea snd sysfillrect soundcore sysimgblt dm_multipath i2c_piix4 kvm_intel scsi_dh serio_raw kvm mac_hid lp parport 8139too psmous
e 8139cp mii floppy pata_acpi
Mar 27 15:15:40 compute kernel: [ 436.100002] CPU: 5 PID: 68 Comm: ksmd Not tainted 3.13.0-46-generic #79-Ubuntu
Mar 27 15:15:40 compute kernel: [ 436.100002] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Mar 27 15:15:40 compute kernel: [ 436.100002] task: ffff8802306db000 ti: ffff8802306e4000 task.ti: ffff8802306e4000
Mar 27 15:15:40 compute kernel: [ 436.100002] RIP: 0010:[<ffffffff810dbf56>] [<ffffffff810dbf56>] generic_exec_single+0x86/0xb0
Mar 27 15:15:40 compute kernel: [ 436.100002] RSP: 0018:ffff8802306e5c00 EFLAGS: 00000202
Mar 27 15:15:40 compute kernel: [ 436.100002] RAX: 0000000000000006 RBX: ffff8802306e5bd0 RCX: 0000000000000005
Mar 27 15:15:40 compute kernel: [ 436.100002] RDX: ffffffff8180ade0 RSI: 0000000000000000 RDI: 0000000000000286
Mar 27 15:15:40 compute kernel: [ 436.100002] RBP: ffff8802306e5c30 R08: ffffffff8180adc8 R09: ffff880232989b48
Mar 27 15:15:40 compute kernel: [ 436.100002] R10: 0000000000000867 R11: 0000000000000000 R12: 0000000000000000
Mar 27 15:15:40 compute kernel: [ 436.100002] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Mar 27 15:15:40 compute kernel: [ 436.100002] FS: 0000000000000000(0000) GS:ffff88023fd40000(0000) knlGS:0000000000000000
Mar 27 15:15:40 compute kernel: [ 436.100002] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
Mar 27 15:15:40 compute kernel: [ 436.100002] CR2: 00007fb0557bf000 CR3: 0000000036b7d000 CR4: 00000000000026e0
Mar 27 15:15:40 compute kernel: [ 436.100002] Stack:
Mar 27 15:15:40 compute kernel: [ 436.100002] ffff88023fd13f80 0000000000000004 0000000000000005 ffffffff81d14300
Mar 27 15:15:40 compute kernel: [ 436.100002] ffffffff8105c7a0 ffff88023212c380 ffff8802306e5ca8 ffffffff810dc065
Mar 27 15:15:40 compute kernel: [ 436.100002] 00000000000134c0 00000000000134c0 ffff88023fd13f80 ffff88023fd13f80
Mar 27 15:15:40 compute kernel: [ 436.100002] Call Trace:
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8105c7a0>] ? leave_mm+0x80/0x80
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff810dc065>] smp_call_function_single+0xe5/0x190
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8105c7a0>] ? leave_mm+0x80/0x80
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffffa008c21a>] ? kvm_handle_hva_range+0x11a/0x180 [kvm]
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffffa008f300>] ? rmap_write_protect+0x80/0x80 [kvm]
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff810dc496>] smp_call_function_many+0x286/0x2d0
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8105c7a0>] ? leave_mm+0x80/0x80
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8105c8f7>] native_flush_tlb_others+0x37/0x40
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8105cbf6>] flush_tlb_page+0x56/0xa0
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8118a4c8>] ptep_clear_flush+0x48/0x60
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8119cd9f>] try_to_merge_with_ksm_page+0x14f/0x650
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8119de36>] ksm_do_scan+0xb96/0xdb0
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8119e0cf>] ksm_scan_thread+0x7f/0x200
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff810ab100>] ? prepare_to_wait_event+0x100/0x100
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8119e050>] ? ksm_do_scan+0xdb0/0xdb0
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8108b592>] kthread+0xd2/0xf0
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8108b4c0>] ? kthread_create_on_node+0x1c0/0x1c0
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff81731ccc>] ret_from_fork+0x7c/0xb0
Mar 27 15:15:40 compute kernel: [ 436.100002] [<ffffffff8108b4c0>] ? kthread_create_on_node+0x1c0/0x1c0
Mar 27 15:15:40 compute kernel: [ 436.100002] Code: 4c 89 23 48 89 4b 08 48 89 19 48 89 55 d0 e8 f2 d1 64 00 4c 3b 65 d0 74 23 45 85 ed 75 09
 eb 0d 0f 1f 44 00 00 f3 90 f6 43 20 01 <75> f8 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 44 89 f7 ff
Mar 27 15:16:08 compute kernel: [ 464.100002] BUG: soft lockup - CPU#5 stuck for 23s! [ksmd:68]

I've got to keep working to get this environment up for a test, but if any specific logs or tests can be helpful, let me know and I'll see what I can provide.