Red Hat, Inc.

Luiz Capitulino

Marcelo Wormsbecker Tosatti

Henri Han Van Riel

David Hildenbrand

Henri Van Riel

A system includes at least one memory device, at least one processor in communication with the at least one memory device, a guest operating system (OS) associated with a device driver, and an out-of-memory (OOM) handler executing on the at least one processor. The OOM handler is configured to locate a memory device of the at least one memory device, send an out-of-memory request to the device driver that is associated with the memory device, and receive a response from the memory device. The device driver is configured to query an amount of unusable device memory, request to plug the unusable device memory, and report the previously unusable device memory as now usable memory.

Dynamic virtual machine memory allocation

A system includes a hypervisor, virtual machine(s), and virtual processor(s). The virtual processor(s) includes a real time virtual processor and a housekeeping virtual processor. The housekeeping virtual processor is configured to initiate a non-preemptible task and responsive to initiating the non-preemptible task, increment a counter value from an initial counter value. The housekeeping virtual processor is also configured to complete the non-preemptible task and responsive to completing the non-preemptible task, decrement the counter value towards the initial counter value. Responsive to the counter value reaching the initial counter value, the virtual housekeeping processor is configured to check a flag set by the hypervisor. Responsive to checking the flag, the housekeeping process is configured to execute a hypercall to yield a processor associated with the housekeeping virtual processor.

Housekeeping virtual processor overcommit for real time virtualization

A system and methods are disclosed for configuring a virtualized system for real-time response from virtual machines (VMs). In accordance with one embodiment, a VM request is received, where the request specifies a number N of virtual processors for executing real-time tasks, and where N is a positive integer. In response to the VM request, a plurality of physical processors are partitioned into a first subset dedicated to real-time tasks and a second subset dedicated to non-real-time tasks, the first subset having at least N physical processors, and one or more commands are submitted to one or both of a hypervisor and a guest OS of a first VM to configure the first VM to have N virtual processors dedicated to real-time tasks and a set of additional virtual processors dedicated to non-real-time tasks.

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Gaineau, Canada

Luiz Capitulino