kernel: BUG: soft lockup detected on CPU#1!

[Naoki]

Anybody else? 2.6.18-1.2798.fc6xen

kernel: BUG: soft lockup detected on CPU#1!
kernel:  [<c040571a>] dump_trace+0x69/0x1af
kernel:  [<c0405878>] show_trace_log_lvl+0x18/0x2c
kernel:  [<c0405e18>] show_trace+0xf/0x11
kernel:  [<c0405e47>] dump_stack+0x15/0x17
kernel:  [<c0441961>] softlockup_tick+0xad/0xc4
kernel:  [<c0409290>] timer_interrupt+0x54b/0x593
kernel:  [<c0441be6>] handle_IRQ_event+0x27/0x51
kernel:  [<c0441ca6>] __do_IRQ+0x96/0xf2
kernel:  [<c0406ca8>] do_IRQ+0x9e/0xbc
kernel:  =======================

No idea what was happening at the time that might explain this.