摘要:
Non-contiguous or tiled payload data are efficiently transferred between peers over a fabric. Specifically, a client transfers a byte enable message to a peer device via a mailbox mechanism, where the byte enable message specifies which bytes of the payload data being transferred via the data packet are to be written to the frame buffer on the peer device and which bytes are not to be written. The client transfers the non-contiguous or tiled payload payload data to the peer device. Upon receiving the payload data, the peer device writes bytes from the payload data into the target frame buffer for only those bytes enabled via the byte enable message. One advantage of the present invention is that non-contiguous or tiled data are transferred over a fabric with improved efficiency.
摘要:
Deadlocks are avoided by marking read requests issued by a parallel processor to system memory as “special.” Read completions associated with read requests marked as special are routed on virtual channel 1 of the PCIe bus. Data returning on virtual channel 1 cannot become stalled by write requests in virtual channel 0, thus avoiding a potential deadlock.
摘要:
Deadlocks are avoided by marking read requests issued by a parallel processor to system memory as “special.” Read completions associated with read requests marked as special are routed on virtual channel 1 of the PCIe bus. Data returning on virtual channel 1 cannot become stalled by write requests in virtual channel 0, thus avoiding a potential deadlock.
摘要:
A method and apparatus for providing peer-to-peer data transfer through an interconnecting fabric. The method and apparatus enable a first device to read and/or write data to/from a local memory of a second device by communicating read and write requests across the interconnectivity fabric. Such data transfer can be performed even when the communication protocol of the interconnectivity fabric does not permit such transfers.
摘要:
A method and apparatus for providing peer-to-peer data transfer through an interconnecting fabric. The method and apparatus enable a first device to read and/or write data to/from a local memory of a second device by communicating read and write requests across the interconnectivity fabric. Such data transfer can be performed even when the communication protocol of the interconnectivity fabric does not permit such transfers.
摘要:
Methods, apparatuses, and systems are presented for performing asynchronous communications involving using an asynchronous interface to send signals between a source device and a plurality of client devices, the source device and the plurality of client devices being part of a processing unit capable of performing graphics operations, the source device being coupled to the plurality of client devices using the asynchronous interface, wherein the asynchronous interface includes at least one request signal, at least one address signal, at least one acknowledge signal, and at least one data signal, and wherein the asynchronous interface operates in accordance with at least one programmable timing characteristic associated with the source device.
摘要:
A time slice group (TSG) is a grouping of different streams of work (referred to herein as “channels”) that share the same context information. The set of channels belonging to a TSG are processed in a pre-determined order. However, when a channel stalls while processing, the next channel with independent work can be switched to fully load the parallel processing unit. Importantly, because each channel in the TSG shares the same context information, a context switch operation is not needed when the processing of a particular channel in the TSG stops and the processing of a next channel in the TSG begins. Therefore, multiple independent streams of work are allowed to run concurrently within a single context increasing utilization of parallel processing units.
摘要:
A system and method avoids passive release of interrupts in a computer system. The computer system includes a plurality of processors, a plurality of input/output (I/O) devices each capable of issuing interrupts, and an I/O bridge interfacing between the I/O devices and the processors. Interrupts, such as level sensitive interrupts (LSIs), asserted by an I/O device coupled to a specific port of the I/O bridge are sent to a processor for servicing by an interrupt controller, which also sets an interrupt pending flag. Upon dispatching the respective interrupt service routine, the processor generates two ordered messages. The first ordered message is sent to the I/O device that triggered the interrupt, informing it that the interrupt has been serviced. The second ordered message directs the interrupt controller to clear the respective interrupt pending flag. Both messages are sent, in order, to the particular I/O bridge port to which the subject I/O device is coupled. After forwarding the first message to the I/O device, the bridge port forwards the second message to the interrupt controller so that the interrupt can be deasserted before the interrupt pending flag is cleared.
摘要:
A system that supports a high performance, scalable, and efficient I/O port protocol to connect to I/O devices is disclosed. A distributed multiprocessing computer system contains a number of processors each coupled to an I/O bridge ASIC implementing the I/O port protocol. One or more I/O devices are coupled to the I/O bridge ASIC, each I/O device capable of accessing machine resources in the computer system by transmitting and receiving message packets. Machine resources in the computer system include data blocks, registers and interrupt queues. Each processor in the computer system is coupled to a memory module capable of storing data blocks shared between the processors. Coherence of the shared data blocks in this shared memory system is maintained using a directory based coherence protocol. Coherence of data blocks transferred during I/O device read and write accesses is maintained using the same coherence protocol as for the memory system. Data blocks transferred during an I/O device read or write access may be buffered in a cache by the I/O bridge ASIC only if the I/O bridge ASIC has exclusive copies of the data blocks. The I/O bridge ASIC includes a DMA device that supports both in-order and out-of-order DMA read and write streams of data blocks. An in-order stream of reads of data blocks performed by the DMA device always results in the DMA device receiving coherent data blocks that do not have to be written back to the memory module.
摘要:
A method and apparatus for accommodating the speed requirements of a DMA read request from PCI protocol I/O devices attached via a DMA to a multiprocessor system mesh. A bridge between the device controller and the mesh is described which buffers the data from the memory in cache lines from which the data is delivered finally to the I/O device. The system is adaptive in that the number of cache lines required in past reads are remembered and used to determine if the number of cache lines is reduced or increased.