Re: Regarding do_irq code

[Sri Ram Vemulpali <sri.ram.gmu06@xxxxxxxxx>]

I know what rcu is and the synchronization mechanism. I am trying to understand struct rcu_dynticks and what this "rcu_exit_nohz" does in irq_enter context. Is this something related hrtimers. please clarify, thanks.

Regards,

Sri

Thanks,

Sri.

On Thu, Sep 16, 2010 at 7:56 PM, Dave Hylands <dhylands@xxxxxxxxx> wrote:

Hi Sri,

On Thu, Sep 16, 2010 at 2:29 PM, Sri Ram Vemulpali
<sri.ram.gmu06@xxxxxxxxx> wrote:
> 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.

I'd recommend reading up on RCU.
<http://en.wikipedia.org/wiki/Read-copy-update>

and the more interesting stuff can be found in your linux
Documentation/RCU/ directory. Start with the rcu.txt file.

--
Dave Hylands
Shuswap, BC, Canada
http://www.DaveHylands.com/