Nir Weiner 49113d360b KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter ... The hard-coded value 10000 in grow_halt_poll_ns() stands for the initial start value when raising up vcpu->halt_poll_ns. It actually sets the first timeout to the first polling session. This value has significant effect on how tolerant we are to outliers. On the standard case, higher value is better - we will spend more time in the polling busyloop, handle events/interrupts faster and result in better performance. But on outliers it puts us in a busy loop that does nothing. Even if the shrink factor is zero, we will still waste time on the first iteration. The optimal value changes between different workloads. It depends on outliers rate and polling sessions length. As this value has significant effect on the dynamic halt-polling algorithm, it should be configurable and exposed. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Nir Weiner <nir.weiner@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2019-02-20 22:48:50 +01:00
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kvm	KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter	2019-02-20 22:48:50 +01:00
lib	KVM: eventfd: fix NULL deref irqbypass consumer	2017-01-12 14:42:34 +01:00
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