Abstract: In an exemplary embodiment of this disclosure, a system may include a first hypervisor, a second hypervisor, and a shared memory set. The first hypervisor and the second hypervisor run over a single logical partition. The shared memory set is accessible by both the first hypervisor and the second hypervisor, and the first hypervisor is configured to communicate with the second hypervisor by writing to the shared memory. The second hypervisor may provide support for hardware that is not supported by the first hypervisor, which hardware may be accessed by the first hypervisor through communications facilitated by use of the shared memory.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: In an exemplary embodiment of this disclosure, a system may include a first hypervisor, a second hypervisor, and a shared memory set. The first hypervisor and the second hypervisor run over a single logical partition. The shared memory set is accessible by both the first hypervisor and the second hypervisor, and the first hypervisor is configured to communicate with the second hypervisor by writing to the shared memory. The second hypervisor may provide support for hardware that is not supported by the first hypervisor, which hardware may be accessed by the first hypervisor through communications facilitated by use of the shared memory.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: A method for managing memory in a virtual computing system is provided. The method comprises providing updated monitor data for a plurality of data domains in the virtual computing system and determining based upon the updated monitor data provided whether there is a memory constraint in a memory of the virtual computing system. Further, the method comprises calculating based upon the updated monitor data, when the memory constraint is determined, a total release-amount of the memory that is to be released by the virtual computing system in order to relieve the memory constraint and issuing a notification to release the total release-amount of the memory in order to relieve the memory constraint. The method further comprises assessing based upon the updated monitor data, when the memory constraint is ended, a reuse-amount that can be reused by the plurality of virtual guests.

Abstract: A technique for utilizing resources in a virtual machine operating system. The virtual machine operating system comprises a multiplicity of virtual machines. A share of resources is allocated to each of the virtual machines. Utilization by one of the virtual machines of the resources allocated to the one virtual machine is automatically monitored. If the one virtual machine needs additional resources, the one virtual machine is automatically cloned. The clone is allocated a share of the resources taken from the shares of other of the virtual machines, such that the resultant shares allocated to the one virtual machine and the clone together are greater than the share allocated to the one virtual machine before the one virtual machine was cloned. The clone performs work with its resources that would have been performed by the one virtual machine if not for the existence of said clone.

Abstract: A method for managing memory in a virtual computing system is provided. The method comprises providing updated monitor data for a plurality of data domains in the virtual computing system and determining based upon the updated monitor data provided whether there is a memory constraint in a memory of the virtual computing system. Further, the method comprises calculating based upon the updated monitor data, when the memory constraint is determined, a total release-amount of the memory that is to be released by the virtual computing system in order to relieve the memory constraint and issuing a notification to release the total release-amount of the memory in order to relieve the memory constraint. The method further comprises assessing based upon the updated monitor data, when the memory constraint is ended, a reuse-amount that can be reused by the plurality of virtual guests.

Abstract: A method for communication between first and second computer programs having a shared memory. The first computer program has a first work dispatcher for a first work queue. The second computer program has a second work dispatcher for a second work queue. Without causing an interrupt, a message or data is written for the second program from the first program to the shared memory and the second work queue is updated with a work item indicating a message or data for the second program. In association with the updating step, it is determined if the second program is currently busy. If so, the second program is not interrupted regarding the message or data. When the second program subsequently becomes not busy, the second program receives, without an interrupt, and executes the work item to receive the message or data. If the second program was not currently busy, the second program is interrupted to process the message or data on its work queue. This imposes a minimal burden on the second program.

Abstract: A method for managing memory in a virtual computing system is provided. The method comprises providing updated monitor data for a plurality of data domains in the virtual computing system and determining based upon the updated monitor data provided whether there is a memory constraint in a memory of the virtual computing system. Further, the method comprises calculating based upon the updated monitor data, when the memory constraint is determined, a total release-amount of the memory that is to be released by the virtual computing system in order to relieve the memory constraint and issuing a notification to release the total release-amount of the memory in order to relieve the memory constraint. The method further comprises assessing based upon the updated monitor data, when the memory constraint is ended, a reuse-amount that can be reused by the plurality of virtual guests.

Abstract: A technique for utilizing resources in a virtual machine operating system. The virtual machine operating system comprises a multiplicity of virtual machines. A share of resources is allocated to each of the virtual machines. Utilization by one of the virtual machines of the resources allocated to the one virtual machine is automatically monitored. If the one virtual machine needs additional resources, the one virtual machine is automatically cloned. The clone is allocated a share of the resources taken from the shares of other of the virtual machines, such that the resultant shares allocated to the one virtual machine and the clone together are greater than the share allocated to the one virtual machine before the one virtual machine was cloned. The clone performs work with its resources that would have been performed by the one virtual machine if not for the existence of said clone.

Abstract: A method for communication between first and second computer programs having a shared memory. The first computer program has a first work dispatcher for a first work queue. The second computer program has a second work dispatcher for a second work queue. Without causing an interrupt, a message or data is written for the second program from the first program to the shared memory and the second work queue is updated with a work item indicating a message or data for the second program. In association with the updating step, it is determined if the second program is currently busy. If so, the second program is not interrupted regarding the message or data. When the second program subsequently becomes not busy, the second program receives, without an interrupt, and executes the work item to receive the message or data. If the second program was not currently busy, the second program is interrupted to process the message or data on its work queue. This imposes a minimal burden on the second program.

Abstract: A method for communication between first and second computer programs having a shared memory. The first computer program has a first work dispatcher for a first work queue. The second computer program has a second work dispatcher for a second work queue. Without causing an interrupt, a message or data is written for the second program from the first program to the shared memory and the second work queue is updated with a work item indicating a message or data for the second program. In association with the updating step, it is determined if the second program is currently busy. If so, the second program is not interrupted regarding the message or data. When the second program subsequently becomes not busy, the second program receives, without an interrupt, and executes the work item to receive the message or data. If the second program was not currently busy, the second program is interrupted to process the message or data on its work queue. This imposes a minimal burden on the second program.

Abstract: A technique for utilizing resources in a virtual machine operating system. The virtual machine operating system comprises a multiplicity of virtual machines. A share of resources is allocated to each of the virtual machines. Utilization by one of the virtual machines of the resources allocated to the one virtual machine is automatically monitored. If the one virtual machine needs additional resources, the one virtual machine is automatically cloned. The clone is allocated a share of the resources taken from the shares of other of the virtual machines, such that the resultant shares allocated to the one virtual machine and the clone together are greater than the share allocated to the one virtual machine before the one virtual machine was cloned. The clone performs work with its resources that would have been performed by the one virtual machine if not for the existence of said clone.

Abstract: A method for communication between first and second computer programs having a shared memory. The first computer program has a first work dispatcher for a first work queue. The second computer program has a second work dispatcher for a second work queue. Without causing an interrupt, a message or data is written for the second program from the first program to the shared memory and the second work queue is updated with a work item indicating a message or data for the second program. In association with the updating step, it is determined if the second program is currently busy. If so, the second program is not interrupted regarding the message or data. When the second program subsequently becomes not busy, the second program receives, without an interrupt, and executes the work item to receive the message or data. If the second program was not currently busy, the second program is interrupted to process the message or data on its work queue. This imposes a minimal burden on the second program.

Abstract: A computer operating system manages events defined by an application program or another part of the operating system. Each event definition includes one or more attributes of the event which controls some operating system responses to an occurrence of the event. After an occurrence of a defined event, an application program or another part of the operating system signals an event manager. The event manager reads the corresponding event definition to determine a mode of operating the signaller of the event or a process associated with the event signaller. The operating modes include a synchronous mode whereby the event signaller or the associated process should suspend processing until the event is handled, and an asynchronous mode whereby the event signaller or associated processor can continue processing while the event is being handled. After reading the event definition, the event manager advises the event signaller whether to proceed synchronously or asynchonously.

Abstract: A computer operating system manages events of interest to a plurality of event handlers within respective programs. The event handlers are arranged in a sequence for the purpose of receiving sequential notification of an occurrence of the event. When the event occurs, the first event handler in the sequence is notified, and it then handles the event. Then, the first event handler determines if the second event handler in the sequence should be notified of the event. If so, the second event handler in the sequence receives the event notification, handles the event, and then determines if the third event handler in the sequence should be notified. In this manner, the event notification can be propagated from event handler to event handler in the sequence, but any event handler in the sequence which receives the notification can block subsequent propagation of the event notification.

Abstract: A computer operating system manages events. An application program or another part of the operating system defines an event monitor to monitor one or more types of events on its behalf. When each of the monitored events occurs, the event monitor is signalled and stores the event signal. Under certain conditions, the event monitor can notify an event handler, and the event handler can access the stored event signals. The event monitor can be defined and established dynamically, i.e. throughout operation of the computer without stopping or relinking the computer system. In the absence of an event monitor which is interested in an event, signals of the event are nevertheless stored. When an interested event monitor is subsequently established, the previously stored event signals are transferred to the interested event monitor. Thus, the event handler has the benefit of previous event signals.

Abstract: A computer operating system manages events of interest to a plurality of event handlers within respective programs. The event handlers are arranged in a sequence for the purpose of receiving sequential notification of an occurrence of the event. When the event occurs, the first event handler in the sequence is notified, and it then handles the event. Then, the first event handler determines if the second event handler in the sequence should be notified of the event. If so, the second event handler in the sequence receives the event notification, handles the event, and then determines if the third event handler in the sequence should be notified. In this manner, the event notification can be propagated from event handler to event handler in the sequence, but any event handler in the sequence which receives the notification can block subsequent propagation of the event notification.