On Tue, Feb 14, 2012 at 03:18:03PM +0200, Avi Kivity wrote: > 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. Right, that's definitely something I need to explore with the adaptive tickless thing. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>