Hi! I've just built server to use it with KVM. Almost immediately I got this warning with one of my virtual servers (two currently). Apr 7 04:44:02 base kernel: ------------[ cut here ]------------ Apr 7 04:44:02 base kernel: WARNING: at include/linux/kref.h:42 handle_tx+0x613/0x680 [vhost_net]() Apr 7 04:44:02 base kernel: Hardware name: System Product Name Apr 7 04:44:02 base kernel: Modules linked in: tcm_qla2xxx tcm_fc libfc tcm_loop target_core_mod configfs ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_CHECKSUM iptable_mangle bridge stp llc autofs4 sunrpc cpufreq_ondemand ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vhost_net macvtap macvlan tun iTCO_wdt iTCO_vendor_support e1000 acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode i2c_i801 raid456 async_raid6_recov async_pq lpc_ich mfd_core raid6_pq async_xor xor async_memcpy async_tx e1000e xhci_hcd sg wmi ext4(F) mbcache(F) jbd2(F) firewire_ohci(F) firewire_core(F) crc_itu_t(F) sd_mod(F) crc_t10dif(F) aesni_intel(F) ablk_helper(F) cryptd(F) lrw(F) aes_x86_64(F) xts(F) gf128mul(F) ahci(F) libahci(F) qla2xxx(F) scsi_transport_fc(F) scsi_tgt(F) mvsas(F) libsas(F) scsi_transport_sas(F) i915(F) drm_kms_helper(F) drm(F) i2c_ Apr 7 04:44:02 base kernel: algo_bit(F) i2c_core(F) video(F) dm_mirror(F) dm_region_hash(F) dm_log(F) dm_mod(F) [last unloaded: i2c_dev] Apr 7 04:44:02 base kernel: Pid: 17583, comm: vhost-17562 Tainted: GF W 3.8.5 #4 Apr 7 04:44:02 base kernel: Call Trace: Apr 7 04:44:02 base kernel: [<ffffffff8105643f>] warn_slowpath_common+0x7f/0xc0 Apr 7 04:44:02 base kernel: [<ffffffff8105649a>] warn_slowpath_null+0x1a/0x20 Apr 7 04:44:02 base kernel: [<ffffffffa03121c3>] handle_tx+0x613/0x680 [vhost_net] Apr 7 04:44:02 base kernel: [<ffffffffa0311bb1>] ? handle_tx+0x1/0x680 [vhost_net] Apr 7 04:44:02 base kernel: [<ffffffffa0312265>] handle_tx_kick+0x15/0x20 [vhost_net] Apr 7 04:44:02 base kernel: [<ffffffffa030fdfc>] vhost_worker+0x10c/0x1c0 [vhost_net] Apr 7 04:44:02 base kernel: [<ffffffffa030fcf0>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] Apr 7 04:44:02 base kernel: [<ffffffffa030fcf0>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] Apr 7 04:44:02 base kernel: [<ffffffff8107a70e>] kthread+0xce/0xe0 Apr 7 04:44:02 base kernel: [<ffffffff8107a640>] ? kthread_freezable_should_stop+0x70/0x70 Apr 7 04:44:02 base kernel: [<ffffffff8159b86c>] ret_from_fork+0x7c/0xb0 Apr 7 04:44:02 base kernel: [<ffffffff8107a640>] ? kthread_freezable_should_stop+0x70/0x70 Apr 7 04:44:02 base kernel: ---[ end trace b9b0bac0c9fdebba ]--- This kept filling my logs until I noticed these. This also prevented virtual machine & host shutdown. I had to reset the server by force. I think these are related to that: Apr 7 23:46:55 base kernel: INFO: task qemu-kvm:17562 blocked for more than 120 seconds. Apr 7 23:46:55 base kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Apr 7 23:46:55 base kernel: qemu-kvm D ffffffff816105e0 0 17562 1 0x00000084 Apr 7 23:46:55 base kernel: ffff88040d6d5d88 0000000000000086 ffff88040d6d5fd8 0000000000013a80 Apr 7 23:46:55 base kernel: ffff88040d6d4010 0000000000013a80 0000000000013a80 0000000000013a80 Apr 7 23:46:55 base kernel: ffff88040d6d5fd8 0000000000013a80 ffffffff81a14420 ffff88040c878b40 Apr 7 23:46:55 base kernel: Call Trace: Apr 7 23:46:55 base kernel: [<ffffffff815921f9>] schedule+0x29/0x70 Apr 7 23:46:55 base kernel: [<ffffffffa03104a5>] vhost_ubuf_put_and_wait+0x65/0xa0 [vhost_net] Apr 7 23:46:55 base kernel: [<ffffffff8107af90>] ? wake_up_bit+0x40/0x40 Apr 7 23:46:55 base kernel: [<ffffffffa0312595>] vhost_net_set_backend+0x1b5/0x280 [vhost_net] Apr 7 23:46:55 base kernel: [<ffffffffa03129a9>] vhost_net_ioctl+0x149/0x1a0 [vhost_net] Apr 7 23:46:55 base kernel: [<ffffffff8118e59c>] do_vfs_ioctl+0x8c/0x340 Apr 7 23:46:55 base kernel: [<ffffffff8117cca5>] ? vfs_write+0xc5/0x130 Apr 7 23:46:55 base kernel: [<ffffffff810b5b3b>] ? sys_futex+0x7b/0x180 Apr 7 23:46:55 base kernel: [<ffffffff8118e8f1>] sys_ioctl+0xa1/0xb0 Apr 7 23:46:55 base kernel: [<ffffffff8159b919>] system_call_fastpath+0x16/0x1b Is there anything that I can do to help to further debug these? That is if I can get them to occur again. Machine has been running for without incident since last reboot (18 hours). I noticed that there is taint flag but I can't figure out how that happened. I tried to check licenses with modinfo put can't see any modules without GPL or related license. There shouldn't be any tainted modules since I compiled kernel from vanilla 3.8.5 Thanks, Juhani -- Juhani Rautiainen jrauti@xxxxxx -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
