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    SubjectRe: [PATCH RFC V2 3/5] kvm hypervisor : Add two hypercalls to support pv-ticketlock
    On 10/24/2011 02:27 PM, Srivatsa Vaddagiri wrote:
    > Good point. Assuming yield_on_hlt=1, that would allow the vcpu to be put
    > to sleep and let other vcpus make progress.
    > I guess with that change, we can also dropthe need for other hypercall
    > introduced in this patch (kvm_pv_kick_cpu_op()). Essentially a vcpu sleeping
    > because of HLT instruction can be woken up by a IPI issued by vcpu releasing a
    > lock.

    Not if interrupts are disabled. My original plan was to use NMIs for
    wakeups, but it turns out NMIs can be coalesced under certain rare
    circumstances; this requires workarounds by the generic NMI code that
    make NMIs too slow.

    I have a truly marvellous patch that fixes the bug which this
    signature is too narrow to contain.

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      Last update: 2011-10-24 15:13    [W:0.085 / U:75.168 seconds]
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