Abstract: Methods and apparatus for saving and/or restoring state information for virtualized computing systems are described. An example apparatus includes a physical memory and a virtual machine monitor to: in response to a request to suspend operation of a virtual machine, place a trace on a memory page in the physical memory to detect at least one of a read access or a write access that occurs when state information of the virtual machine is saved in response to the request, the memory page associated with virtual memory hosted by the virtual machine, while the virtual machine continues to operate after the request, initiate storing of the virtual memory of the virtual machine, and in response to a trigger of the trace, store an indication that the memory page is an active memory page.

Abstract: A system and related method of operation for migrating the memory of a virtual machine from one NUMA node to another. Once the VM is migrated to a new node, migration of memory pages is performed while giving priority to the most utilized pages, so that access to these pages becomes local as soon as possible. Various heuristics are described to enable different implementations for different situations or scenarios.

Abstract: A system and related method of operation for migrating the memory of a virtual machine from one NUMA node to another. Once the VM is migrated to a new node, migration of memory pages is performed while giving priority to the most utilized pages, so that access to these pages becomes local as soon as possible. Various heuristics are described to enable different implementations for different situations or scenarios.

Abstract: Prior to or while the state of a virtual machine (“VM”) is being saved, such as in connection with the suspension or checkpointing of a VM, a set of one or more “active” memory pages is identified, this set of active memory pages comprising memory pages that are in use within the VM before operation of the VM is suspended. This set of active memory pages may constitute a “working set” of memory pages. To restore the state of the VM and resume operation, in some embodiments, (a) access to persistent storage is restored to the VM, device state for the VM is restored, and one or more of the set of active memory pages are loaded into physical memory; (b) operation of the VM is resumed; and (c) additional memory pages from the saved state of the VM are loaded into memory after operation of the VM has resumed.

Abstract: A system and related method of operation for migrating the memory of a virtual machine from one NUMA node to another. Once the VM is migrated to a new node, migration of memory pages is performed while giving priority to the most utilized pages, so that access to these pages becomes local as soon as possible. Various heuristics are described to enable different implementations for different situations or scenarios.

Abstract: An object structure's header (40) allocates a two-bit synchronization-state field (42) solely to monitor data for implementing synchronization on that object. When the object is locked by a particular execution thread, or when one or more execution threads are waiting for a lock or notification on that object, its header contains a pointer to monitor resources in the form of a linked list of lock records (50, 52, 54) associated with the threads involved. The synchronization-state field (42) ordinarily contains an indication of whether such a linked list exists and, if so, whether its first member is associated with a thread that has a lock on the object. When a thread attempts to gain access to that linked list, it employs an atomic swap operation to place a special busy value in that lock-state field (42) and write its execution-environment pointer into the object's header (40).

Abstract: An object structure's header (40) allocates a two-bit synchronization-state field (42) solely to monitor data for implementing synchronization on that object. When the object is locked by a particular execution thread, or when one or more execution threads are waiting for a lock or notification on that object, its header contains a pointer to monitor resources in the form of a linked list of lock records (50, 52, 54) associated with the threads involved. The synchronization-state field (42) ordinarily contains an indication of whether such a linked list exists and, if so, whether its first member is associated with a thread that has a lock on the object. When a thread attempts to gain access to that linked list, it employs an atomic swap operation to place a special busy value in that lock-state field (42) and write its execution-environment pointer into the object's header (40).