On Tue, Feb 10, 2015 at 03:27:49PM -0500, riel@xxxxxxxxxx wrote: > When running a KVM guest on a system with NOHZ_FULL enabled, and the > KVM guest running with idle=poll mode, we still get wakeups of the > rcuos/N threads. > > This problem has already been solved for user space by telling the > RCU subsystem that the CPU is in an extended quiescent state while > running user space code. > > This patch series extends that code a little bit to make it usable > to track KVM guest space, too. > > I tested the code by booting a KVM guest with idle=poll, on a system > with NOHZ_FULL enabled on most CPUs, and a VCPU thread bound to a > CPU. In a 10 second interval, rcuos/N threads on other CPUs got woken > up several times, while the rcuos thread on the CPU running the bound > and alwasy running VCPU thread never got woken up once. > > Thanks to Christian Borntraeger, Paul McKenney, Paulo Bonzini, > Frederic Weisbecker, and Will Deacon for reviewing and improving > earlier versions of this patch series. > So the patchset look good, thanks everyone. I'm applying the series and will see anything explode. I'll wait until the end of the merge window to push it to Ingo. Thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
