Regarding do_irq code

[Sri Ram Vemulpali]

Hi Guys,

      I got stuck at a function to understand which is called in irq_enter
context.
      This function is rcu_exit_nohz();

      I know rcu is read-copy-update locking mechanism to provide light
weight locking
      to synchronize readers and writers.
      So now the question is what this function rcu_exit_nohz() do in
irq_enter context
      and what is "struct rcu_dynticks" is used for.

      Can anyone please clarify these. Thanks.

Regards,
Sri.