Abstract: An approach is provided in a hypervised computer system where a page table request is at an operating system running in the hypervised computer system. The operating system determines whether the page table request requires the hypervisor to process. If the determination reveals that the page table request requires the hypervisor, then the hypervisor is used to handle the request. However, if the determination reveals that the page table request does not require the hypervisor, then an indicator included in a page table entry corresponding to the request is read to determine if the page table entry is controlled by the operating system or the hypervisor. The operating system is able to update the page table entry if the indicator identifies the page table entry as being operating system controlled.

Abstract: An approach is provided in a hypervised computer system where a page table request is at an operating system running in the hypervised computer system. The operating system determines whether the page table request requires the hypervisor to process. If the determination reveals that the page table request requires the hypervisor, then the hypervisor is used to handle the request. However, if the determination reveals that the page table request does not require the hypervisor, then an indicator included in a page table entry corresponding to the request is read to determine if the page table entry is controlled by the operating system or the hypervisor. The operating system is able to update the page table entry if the indicator identifies the page table entry as being operating system controlled.

Abstract: An approach is provided in a hypervised computer system where a page table request is at an operating system running in the hypervised computer system. The operating system determines whether the page table request requires the hypervisor to process. If the determination reveals that the page table request requires the hypervisor, then the hypervisor is used to handle the request. However, if the determination reveals that the page table request does not require the hypervisor, then an indicator included in a page table entry corresponding to the request is read to determine if the page table entry is controlled by the operating system or the hypervisor. The operating system is able to update the page table entry if the indicator identifies the page table entry as being operating system controlled.

Abstract: An approach is provided in a hypervised computer system where a page table request is at an operating system running in the hypervised computer system. The operating system determines whether the page table request requires the hypervisor to process. If the determination reveals that the page table request requires the hypervisor, then the hypervisor is used to handle the request. However, if the determination reveals that the page table request does not require the hypervisor, then an indicator included in a page table entry corresponding to the request is read to determine if the page table entry is controlled by the operating system or the hypervisor. The operating system is able to update the page table entry if the indicator identifies the page table entry as being operating system controlled.

Abstract: Embodiments of the invention provide methods and systems for reducing the consumption of inter-node bandwidth by communications maintaining coherence between accelerators and CPUs. The CPUs and the accelerators may be clustered on separate nodes in a multiprocessing environment. Each node that contains a shared memory device may maintain a directory to track blocks of shared memory that may have been cached at other nodes. Therefore, commands and addresses may be transmitted to processors and accelerators at other nodes only if a memory location has been cached outside of a node. Additionally, because accelerators generally do not access the same data as CPUs, only initial read, write, and synchronization operations may be transmitted to other nodes. Intermediate accesses to data may be performed non-coherently. As a result, the inter-chip bandwidth consumed for maintaining coherence may be reduced.

Abstract: Embodiments of the invention provide methods and apparatus for increasing the number of page attributes specified by a page table while minimizing an increase in size of the page table. According to embodiments of the invention, attribute index bits may be included within a page table and may be used to determine page attributes stored within an attribute index. Additionally, embodiments of the invention provide a plurality of new page attributes.

Abstract: Embodiments of the invention provide methods and systems for reducing the consumption of inter-node bandwidth by communications maintaining coherence between accelerators and CPUs. The CPUs and the accelerators may be clustered on separate nodes in a multiprocessing environment. Each node that contains a shared memory device may maintain a directory to track blocks of shared memory that may have been cached at other nodes. Therefore, commands and addresses may be transmitted to processors and accelerators at other nodes only if a memory location has been cached outside of a node. Additionally, because accelerators generally do not access the same data as CPUs, only initial read, write, and synchronization operations may be transmitted to other nodes. Intermediate accesses to data may be performed non-coherently. As a result, the inter-chip bandwidth consumed for maintaining coherence may be reduced.

Abstract: The present invention provides a method and apparatus for processing a bus protocol packet in order to provide accelerator support. A component receives a bus protocol packet having a requester identifier. The component looks up an agent routing field. The component routes the bus protocol packet to an accelerator agent based on the agent routing field. It processes the bus protocol packet at the accelerator agent based on the agent routing field.

Abstract: Embodiments of the invention provide methods and systems for reducing the consumption of inter-node bandwidth by communications maintaining coherence between accelerators and CPUs. The CPUs and the accelerators may be clustered on separate nodes in a multiprocessing environment. Each node that contains a shared memory device may maintain a directory to track blocks of shared memory that may have been cached at other nodes. Therefore, commands and addresses may be transmitted to processors and accelerators at other nodes only if a memory location has been cached outside of a node. Additionally, because accelerators generally do not access the same data as CPUs, only initial read, write, and synchronization operations may be transmitted to other nodes. Intermediate accesses to data may be performed non-coherently. As a result, the inter-chip bandwidth consumed for maintaining coherence may be reduced.

Abstract: A method, apparatus and computer program product are provided for implementing conditional packet alterations based upon a transmit port. A selection mechanism is provided for implementing packet alterations. A sequence of frame alteration instructions and transmit port numbers associated with a packet being transmitted is applied to the selection mechanism. The selection mechanism performs alterations on the packet being transmitted responsive to the applied sequence of frame alteration instructions and port numbers associated with the packet. The selection mechanism includes a multiplexer that sequentially receives frame alteration instructions and port numbers associated with a packet being transmitted, and an indirect data array for providing packet alteration data from the indirect data array.

Abstract: In a first aspect, a first method of synchronizing a plurality of processors of a system is provided. The first method includes the steps of (1) modifying a peripheral component interconnect express (PCIe) protocol to include a completion status encode associated with a synchronization command that indicates whether a condition of the synchronization command is met; (2) providing a system including (a) a memory; (b) a first processor coupled to the memory; (c) a second processor; and (d) an interconnect coupling the second processor to the first processor and the memory; and (3) employing the modified PCIe protocol on the interconnect. Numerous other aspects are provided.

Abstract: Embodiments of the invention provide methods and apparatus for increasing the number of page attributes specified by a page table while minimizing an increase in size of the page table. According to embodiments of the invention, attribute index bits may be included within a page table and may be used to determine page attributes stored within an attribute index. Additionally, embodiments of the invention provide a plurality of new page attributes.

Abstract: A method, apparatus and computer program product are provided for implementing conditional packet alterations based upon a transmit port. A selection mechanism is provided for implementing packet alterations. A sequence of frame alteration instructions and transmit port numbers associated with a packet being transmitted is applied to the selection mechanism. The selection mechanism performs alterations on the packet being transmitted responsive to the applied sequence of frame alteration instructions and port numbers associated with the packet. The selection mechanism includes a multiplexer that sequentially receives frame alteration instructions and port numbers associated with a packet being transmitted, and an indirect data array for providing packet alteration data from the indirect data array.

Abstract: A method and apparatus are provided for efficiently managing limited resources is a given computer system. The system utilizes a token manager that assigns tokens to groups of associated requestors. The tokens are then utilized by the requesters to occupy the given resource. The allocation of these tokens, thus, prevents such problems as denial of service due to a lack of available resources.

Abstract: The present invention provides a method and apparatus for processing a bus protocol packet in order to provide accelerator support. A component receives a bus protocol packet having a requester identifier. The component looks up an agent routing field. The component routes the bus protocol packet to an accelerator agent based on the agent routing field. It processes the bus protocol packet at the accelerator agent based on the agent routing field.

Abstract: A method, apparatus and computer program product are provided for implementing conditional packet alterations based upon a transmit port. A selection mechanism is provided for implementing packet alterations. A sequence of frame alteration instructions and transmit port numbers associated with a packet being transmitted is applied to the selection mechanism. The selection mechanism performs alterations on the packet being transmitted responsive to the applied sequence of frame alteration instructions and port numbers associated with the packet. The selection mechanism includes a multiplexer that sequentially receives frame alteration instructions and port numbers associated with a packet being transmitted, and an indirect data array for providing packet alteration data from the indirect data array.

Abstract: In a first aspect, a first method of synchronizing a plurality of processors of a system is provided. The first method includes the steps of (1) modifying a peripheral component interconnect express (PCIe) protocol to include a completion status encode associated with a synchronization command that indicates whether a condition of the synchronization command is met; (2) providing a system including (a) a memory; (b) a first processor coupled to the memory; (c) a second processor; and (d) an interconnect coupling the second processor to the first processor and the memory; and (3) employing the modified PCIe protocol on the interconnect. Numerous other aspects are provided.

Abstract: A system and method for performing computer processing operations in a data processing system includes a multithreaded processor and thread switch logic. The multithreaded processor is capable of switching between two or more threads of instructions which can be independently executed. Each thread has a corresponding state in a thread state register depending on its execution status. The thread switch logic contains a thread switch control register to store the conditions upon which a thread switch will occur. The thread switch logic has a time-out register which forces a thread switch when execution of the active thread in the multithreaded processor exceeds a programmable period of time. Thread switch logic also has a forward progress count register to prevent repetitive thread switching between threads in the multithreaded processor. Thread switch logic also is responsive to a software manager capable of changing the priority of the different threads and thus superseding thread switch events.

Abstract: A system and method for performing computer processing operations in a data processing system includes a multithreaded processor and thread switch logic. The multithreaded processor is capable of switching between two or more threads of instructions which can be independently executed. Each thread has a corresponding state in a thread state register depending on its execution status. The thread switch logic contains a thread switch control register to store the conditions upon which a thread switch can occur. Upon the occurrence of a thread switch event, the state and priority of all threads are dynamically interrogated to determine which thread should be the active thread executing the processor. The thread switch logic has a time-out register which forces a thread switch when execution of the active thread in the multithreaded processor exceeds a programmable period of time.

Abstract: A system and method for performing computer processing operations in a data processing system includes a multithreaded processor and thread switch logic. The multithreaded processor is capable of switching between two or more threads of instructions which can be independently executed. Each thread has a corresponding state in a thread state register depending on its execution status. The thread switch logic contains a thread switch control register to store the conditions upon which a thread switch will occur. The thread switch logic has a time-out register which forces a thread switch when execution of the active thread in the multithreaded processor exceeds a programmable period of time. Thread switch logic also has a forward progress count register to prevent repetitive unproductive thread switching between threads in the multithreaded processor. Thread switch logic also is responsive to a software manager capable of changing the priority of the different threads and thus superseding thread switch events.