On 27/02/14 13:11, Paolo Bonzini wrote: > Il 27/02/2014 13:11, David Vrabel ha scritto: >>> > This patch adds para-virtualization support to the queue spinlock code >>> > by enabling the queue head to kick the lock holder CPU, if known, >>> > in when the lock isn't released for a certain amount of time. It >>> > also enables the mutual monitoring of the queue head CPU and the >>> > following node CPU in the queue to make sure that their CPUs will >>> > stay scheduled in. >> I'm not really understanding how this is supposed to work. There >> appears to be an assumption that a guest can keep one of its VCPUs >> running by repeatedly kicking it? This is not possible under Xen and I >> doubt it's possible under KVM or any other hypervisor. > > KVM allows any VCPU to wake up a currently halted VCPU of its choice, > see Documentation/virtual/kvm/hypercalls.txt. But neither of the VCPUs being kicked here are halted -- they're either running or runnable (descheduled by the hypervisor). David _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
