Messages in this thread | | | Subject | Re: [PATCH 2/3] kvm hypervisor : Add hypercalls to support pv-ticketlock | From | Peter Zijlstra <> | Date | Wed, 19 Jan 2011 18:50:15 +0100 |
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On Wed, 2011-01-19 at 22:53 +0530, Srivatsa Vaddagiri wrote: > On Wed, Jan 19, 2011 at 10:42:39PM +0530, Srivatsa Vaddagiri wrote: > > Add two hypercalls to KVM hypervisor to support pv-ticketlocks. > > > > KVM_HC_WAIT_FOR_KICK blocks the calling vcpu until another vcpu kicks it or it > > is woken up because of an event like interrupt. > > One possibility is to extend this hypercall to do a directed yield as well, > which needs some more thought. Another issue that needs to be resolved with > pv-ticketlocks is the impact on intra-VM fairness. A guest experiencing heavy > contention can keep yielding cpu, allowing other VMs to get more time than they > deserve.
No, yield sucks, if you know the owner you can do actual PI.
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