On Wed, Feb 01, 2012 at 02:06:07PM -0600, Christoph Lameter wrote: > On Wed, 1 Feb 2012, Paul E. McKenney wrote: > > > On Wed, Feb 01, 2012 at 06:35:22PM +0100, Peter Zijlstra wrote: > > > On Sun, 2012-01-29 at 10:25 +0200, Gilad Ben-Yossef wrote: > > > > > > > > If this is of interest, I keep a list tracking global IPI and global > > > > task schedulers sources in the core kernel here: > > > > https://github.com/gby/linux/wiki. > > > > > > You can add synchronize_.*_expedited() to the list, it does its best to > > > bash the entire machine in order to try and make RCU grace periods > > > happen fast. > > > > I have duly added "Make synchronize_sched_expedited() avoid IPIing idle > > CPUs" to http://kernel.org/pub/linux/kernel/people/paulmck/rcutodo.html. > > > > This should not be hard once I have built up some trust in the new > > RCU idle-detection code. It would also automatically apply to > > Frederic's dyntick-idle userspace work. > > Could we also apply the same approach to processors busy doing > computational work? In that case the OS is also not needed. Interrupting > these activities is impacting on performance and latency. Yep, that is in fact what Frederic's dyntick-idle userspace work does. Thanx, Paul -- 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>