Issue

• 多くの仮想 CPU を 10 秒 (以内) オフラインにすると、eth0 で NETDEV WATCHDOG タイムアウトエラーが発生します。 確認したインスタンスでは、for-loop で以下を行うことで、できるだけ早く 20 個の仮想 CPU がオフラインになろうとしています。

echo 0 > /sys/devices/system/cpu/cpuX/online

• カーネルのリングバッファーに以下のメッセージが出力されます。

CPU 7 is now offline
CPU 7 offline:Remove Rx thread
Breaking affinity for irq 15
CPU 6 is now offline
CPU 6 offline:Remove Rx thread
CPU 5 is now offline
CPU 5 offline:Remove Rx thread
CPU 4 is now offline
CPU 4 offline:Remove Rx thread
NETDEV WATCHDOG: eth0: transmit timed out
eth0: tx hang
eth0: resetting
NETDEV WATCHDOG: eth0: transmit timed out
eth0: tx hang
NETDEV WATCHDOG: eth0: transmit timed out
eth0: tx hang
..
NMI received for unknown reason 20
WARNING: at kernel/softirq.c:138 local_bh_enable()

Call Trace:
 <NMI>  [<ffffffff8002c131>] local_bh_enable+0x44/0x99
 [<ffffffff80058239>] __ip_route_output_key+0xaf/0x816
 [<ffffffff8025634c>] ip_route_output_flow+0x18/0x1ee
 [<ffffffff8025abbf>] ip_send_reply+0x11a/0x25b
 [<ffffffff80266a14>] tcp_v4_send_reset+0x104/0x141
 [<ffffffff80037d93>] ip_route_input+0xb2f/0xcbe
 [<ffffffff80027978>] tcp_v4_rcv+0xa2c/0xa71
 [<ffffffff80034c37>] ip_local_deliver+0x19f/0x265
 [<ffffffff80035dc9>] ip_rcv+0x539/0x57c
 [<ffffffff8002108c>] netif_receive_skb+0x48c/0x4ae
 [<ffffffff881fc15d>] :vmxnet3:vmxnet3_rq_rx_complete+0xa0f/0xb7f
 [<ffffffff881fc33a>] :vmxnet3:vmxnet3_do_poll+0x6d/0x88
 [<ffffffff881fde52>] :vmxnet3:vmxnet3_netpoll+0x27/0x30
 [<ffffffff80246cfd>] netpoll_poll_dev+0x47/0x36c
 [<ffffffff802470fc>] netpoll_send_skb_on_dev+0xda/0xef
 [<ffffffff886ee0e1>] :netconsole:write_msg+0x49/0x60
 [<ffffffff800941f6>] __call_console_drivers+0x5b/0x69
 [<ffffffff80017329>] release_console_sem+0x13e/0x200
 [<ffffffff800949eb>] vprintk+0x2b2/0x317
 [<ffffffff80094aa2>] printk+0x52/0xbd
 [<ffffffff8006503a>] oops_begin+0x5e/0x65
 [<ffffffff80065263>] die_nmi+0x24/0xa3
 [<ffffffff80079832>] do_nmi_callback2+0x33/0x3c
 [<ffffffff8006561c>] default_do_nmi+0x94/0x22f
 [<ffffffff80065903>] do_nmi+0x43/0x61
 [<ffffffff80064ecf>] nmi+0x7f/0x88
 [<ffffffff8006bdfb>] default_idle+0x0/0x50
 [<ffffffff8006be24>] default_idle+0x29/0x50
 <<EOE>>  [<ffffffff80049614>] cpu_idle+0x95/0xb8
 [<ffffffff80471809>] start_kernel+0x220/0x225
 [<ffffffff8047122f>] _sinittext+0x22f/0x236

WARNING: at net/core/skbuff.c:417 skb_release_head_state()

Call Trace:
 <NMI>  [<ffffffff80236997>] skb_release_head_state+0xa2/0xf8
 [<ffffffff800291d4>] __kfree_skb+0x9/0x1a
 [<ffffffff80240653>] __neigh_event_send+0x115/0x167
 [<ffffffff80057157>] neigh_resolve_output+0x81/0x269
 [<ffffffff80059102>] ip_append_data+0x697/0xa43
 [<ffffffff800322f2>] ip_output+0x2ae/0x2dd
 [<ffffffff8025a9c5>] ip_push_pending_frames+0x381/0x461
 [<ffffffff8025aca4>] ip_send_reply+0x1ff/0x25b
 [<ffffffff80266a14>] tcp_v4_send_reset+0x104/0x141
 [<ffffffff80037d93>] ip_route_input+0xb2f/0xcbe
 [<ffffffff80027978>] tcp_v4_rcv+0xa2c/0xa71
 [<ffffffff80034c37>] ip_local_deliver+0x19f/0x265
 [<ffffffff80035dc9>] ip_rcv+0x539/0x57c
 [<ffffffff8002108c>] netif_receive_skb+0x48c/0x4ae
 [<ffffffff881fc15d>] :vmxnet3:vmxnet3_rq_rx_complete+0xa0f/0xb7f
 [<ffffffff881fc33a>] :vmxnet3:vmxnet3_do_poll+0x6d/0x88
 [<ffffffff881fde52>] :vmxnet3:vmxnet3_netpoll+0x27/0x30
 [<ffffffff80246cfd>] netpoll_poll_dev+0x47/0x36c
 [<ffffffff802470fc>] netpoll_send_skb_on_dev+0xda/0xef
 [<ffffffff886ee0e1>] :netconsole:write_msg+0x49/0x60
 [<ffffffff800941f6>] __call_console_drivers+0x5b/0x69
 [<ffffffff80017329>] release_console_sem+0x13e/0x200
 [<ffffffff800949eb>] vprintk+0x2b2/0x317
 [<ffffffff80094aa2>] printk+0x52/0xbd
 [<ffffffff8006503a>] oops_begin+0x5e/0x65
 [<ffffffff80065263>] die_nmi+0x24/0xa3
 [<ffffffff80079832>] do_nmi_callback2+0x33/0x3c
 [<ffffffff8006561c>] default_do_nmi+0x94/0x22f
 [<ffffffff80065903>] do_nmi+0x43/0x61
 [<ffffffff80064ecf>] nmi+0x7f/0x88
 [<ffffffff8006bdfb>] default_idle+0x0/0x50
 [<ffffffff8006be24>] default_idle+0x29/0x50
 <<EOE>>  [<ffffffff80049614>] cpu_idle+0x95/0xb8
 [<ffffffff80471809>] start_kernel+0x220/0x225
 [<ffffffff8047122f>] _sinittext+0x22f/0x236

• FLIP アクティビティの最中に、サーバーがハングアップします。