Re: [v7 0/8] Reduce cross CPU IPI interference

[Avi Kivity]

On 02/10/2012 03:39 AM, Frederic Weisbecker wrote:
> > 
> > As long as the code doesn't enter RCU read-side critical sections in
> > the time between rcu_idle_enter() and rcu_idle_exit(), this should
> > work fine.
>
> This should work fine yeah but further the correctness, I wonder if this
> is going to be a win.
>
> We use rcu_idle_enter() in idle to avoid to keep the tick for RCU. But
> what about falling into guest mode? I guess the tick is kept there
> so is it going to be a win in throughput or something to use rcu_idle_enter()?

We could disable the tick while in guest mode as well.  Interrupts in
guest mode are even more expensive than interrupts in user mode.

-- 
error compiling committee.c: too many arguments to function

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