rcu_sched_state detected stall, no stack trace

Hi,

I am running vanilla kernel 3.0.23 . I am trying to add some 6K and more
IPv6 IPSec tunnels.
I am getting these warnings in dmesg close to 6k tunnels, after which
the kernel hangs and have to reboot the kernel.

[ 1511.045261] INFO: rcu_sched_state detected stall on CPU 4 (t=300000
jiffies) [ 1534.736899] INFO: rcu_bh_state detected stalls on
CPUs/tasks: { 4} (detected by 13, t=300002 jiffies)

I am not getting any back-trace also, to figure out what is actually
causing the stall to happen.

Could someone help to figure out the issue.

Regards,
Prashant