HvNotifyLongSpinWait function

The HvNotifyLongSpinWait function informs the hypervisor that the calling virtual processor is attempting to acquire a resource that is potentially held by another virtual processor within the same partition.

Syntax

HV_STATUS  HvNotifyLongSpinWait(
  _In_  HV_INPUT_NOTIFY_LONG_SPINWAIT SpinWaitInfo
);

Parameters

SpinWaitInfo [in]

An HV_INPUT_NOTIFY_LONG_SPINWAIT value that identifies the accumulated count that the guest operating system was spinning. HV_INPUT_NOTIFY_LONG_SPINWAIT is defined as an unsigned 64-bit (UINT64) value.

Return value

HvNotifyLongSpinWait returns no error status. HvNotifyLongSpinWait returns only HV_STATUS_SUCCESS because HvNotifyLongSpinWait is an advisory hypercall function.

Remarks

HvNotifyLongSpinWait can be used to improve the scalability of multiprocessor virtual machines.

A partition calls HvNotifyLongSpinWait to inform the hypervisor of a long spinlock acquire failure. The hypervisor can use this information to make better scheduling decisions for notifying the virtual processor and the virtual processor's partition.

Native Interface

Requirements

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Build date: 11/16/2013