Microsoft Technology Licensing, LLC

Thomas Fahrig

David N Cutler

Arun Upadhyaya Kishan

Rene Antonio Vega

John Te-Jui Sheu

Yau Ning Chin

Mehmet Iyigun

Mark James McNulty

Parag Sharma

Gregory John Colombo

James Andrew Goossen

Logananth Seetharaman

Graham Wong

Fabian Samuel Tillier

Mai Ghaly

Thobias Jones

Michael Charles Crandall

Steven Michel Pronovost

Paul Joseph Wolfteich

Blaine Craig Hauglie

Steve Michel Pronovost

Mark James Mcnulty

David Neil Cutler

A user can select a capacity setting for a transitional partition that determines the allocation between a low-density partition and a high-density partition in the transitional partition. The transitional partition can dynamically change among multiple settings having different capacities for the low-density partition. If the current setting of the transitional partition does not efficiently utilize the available storage space based on the user's preferences for storing different types of data in the low-density partition and the high-density partition, then the user can choose to change the transitional partition to a different setting that better suits the individual user's storage allocation preferences. Therefore, valuable storage space will not be under-utilized but instead will be repurposed for more efficient use by converting a low-density partition to a high-density partition, and vice versa.

User selectable transitional storage partition

The present disclosure relates to devices, methods, and computer-readable medium for saving and restoring physical hardware states and virtual machine (VM) states for an application actively being executed on a virtual machine by a user on a computer device. The devices, methods, and computer-readable medium may allow a user to suspend a current state of an application session and save the VM and memory state to persistent storage, and later resume the execution of the saved application session by reading the state back into memory and restoring the VM state.

Saving and restoring virtual machine states and hardware states for application content

A computing system includes a parent partition, child partitions, a hypervisor, shared memories each associated with one of the child partitions, and trigger pages each associated with one of the child partitions. The hypervisor receives a system event signal from one of the child partitions and, in response to receiving the system event signal, accesses the trigger page associated with that child partition. The hypervisor determines whether the trigger page indicates whether data is available to be read from the shared memory associated with the child partition. The hypervisor can send an indication to either the parent partition or the child partitions that data is available to be read from the shared memory associated with the child partition if the hypervisor determines that the trigger page indicates that data is available to be read from the shared memory associated with the child partition.

Virtual machine trigger

Computerized methods, computer systems, and computer-readable media for governing how virtual processors are scheduled to particular logical processors are provided. A scheduler is employed to balance a load imposed by virtual machines, each having a plurality of virtual processors, across various logical processors (comprising a physical machine) that are running threads in parallel. The threads are issued by the virtual processors and often cause spin waits that inefficiently consume capacity of the logical processors that are executing the threads. Upon detecting a spin-wait state of the logical processor(s), the scheduler will opportunistically grant time-slice extensions to virtual processors that are running a critical section of code, thus, mitigating performance loss on the front end. Also, the scheduler will mitigate performance loss on the back end by opportunistically de-scheduling then rescheduling a virtual machine in a spin-wait state to render the logical processor(s) available for other work in the interim.

Opportunistically scheduling and adjusting time slices

Embodiments disclosed herein are related to systems, methods, and computer readable medium for allocating one or more system resources for the exclusive use of an application. The embodiments include receiving a request for an exclusive allocation of one or more system resources for a first application, the one or more system resources being useable by the first application and one or more second applications; determining an appropriate amount of the one or more system resources that are to be allocated exclusively to the first application; and partitioning the one or more system resources into a first portion that is allocated for the exclusive use of the first application and a second portion that is not allocated for the exclusive use of the first application, the second portion being available for the use of the one or more second applications.

Operating system support for game mode

Various aspects are disclosed herein for attenuating spin waiting in a virtual machine environment comprising a plurality of virtual machines and virtual processors. Selected virtual processors can be given time slice extensions in order to prevent such virtual processors from becoming de-scheduled (and hence causing other virtual processors to have to spin wait). Selected virtual processors can also be expressly scheduled so that they can be given higher priority to resources, resulting in reduced spin waits for other virtual processors waiting on such selected virtual processors. Finally, various spin wait detection techniques can be incorporated into the time slice extension and express scheduling mechanisms, in order to identify potential and existing spin waiting scenarios.

Efficient detection and response to spin waits in multi-processor virtual machines

Idle virtual machine partitions in a virtualized computing environment are consolidated onto one or more idle logical processors. A hypervisor monitors the individual utilization of multiple virtual machine partitions in a computing environment and determines which virtual machine partitions are idle. The hypervisor also monitors the individual utilization of multiple logical processors in the computing environment and determines which logical processors are idle. The hypervisor schedules all of the idle virtual machine partitions on one or more of the idle logical processors. This can improve the performance for work-generating partitions and ensure compliance with service level agreements. At the same time, it can provide efficient power management in that is consolidates idle virtual machines onto a smaller subset of logical processors.

Consolidation of idle virtual machines on idle logical processors

One embodiment illustrated herein includes a method that may be practiced in a computing environment. The method includes acts for providing direct access to hardware to virtual machines. The method includes determining that a virtual machine should have access to a piece of hardware. The method further includes a virtual machine requesting access to the hardware from the host wherein a host is a special partition that controls the physical hardware of a computing system and manages virtual machines. The method further includes the host configuring the hardware to allow access to the hardware directly by the virtual machine by the host mapping hardware resources into the virtual machine's address space. The method further includes the virtual machine directly accessing the hardware without going through the host once the hardware has been configured by the host.

Application acceleration in a virtualized environment

Computerized methods, computer systems, and computer-readable media for governing how virtual processors are scheduled to particular logical processors are provided. A scheduler is employed to balance a CPU-intensive workload imposed by virtual machines, each having a plurality of virtual processors supported by a root partition, across various logical processors that are running threads and input/output (I/O) operations in parallel. Upon measuring a frequency of the I/O operations performed by a logical processor that is mapped to the root partition, a hardware-interrupt rate is calculated as a function of the frequency. The hardware-interrupt rate is compared against a predetermined threshold rate to determine a level of an I/O-intensive workload being presently carried out by the logical processor. When the hardware-interrupt rate surpasses the predetermined threshold rate, the scheduler refrains from allocating time slices on the logical processor to the virtual machines.

Efficient input/output-aware multi-processor virtual machine scheduling

Timers are managed in a multiprocessing environment. Some timers are local to a given logical processor; such a local timer is inserted on and will be canceled only from that logical processor. Other timers are global to a logical processor. A global timer which was inserted on a given logical processor may be canceled from that logical processor or from another logical processor. Global timers are serviced in response to expiration of an associated local timer.

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Redmond, WA, United States of America

Thomas Fahrig