摘要:
The temporary storage of a memory line to be stored in a cache while waiting for another memory line to be evicted from the cache is disclosed. A method includes evicting a first memory line currently stored in the cache and storing a second memory line not currently stored in the cache in its place. While the first memory line is being evicted, such as by first being inserted into an eviction queue, the second memory line is temporarily stored in a buffer. The buffer may be a data transfer buffer (DTB). Upon eviction of the first memory line, the second memory line is moved from the buffer into the cache.
摘要:
Each node of multinode computer system includes an interrupt controller, a pair of send and receive queues, and a state machine for communicating interrupts between nodes. The communication among the interrupt controller, the state machine, and the queues is coordinated by a queue manager. For sending an interrupt, the interrupt controller accepts an interrupt placed on a bus within the node and intended for another node and stores it in the send queue. The controller then notifies the interrupt source that the interrupt has been accepted before it is transmitted to other node. The interrupt has a first form suitable for transmission on the bus. A state machine within the node takes the interrupt from the send queue and puts the interrupt into a second form suitable for transmission across a network connecting the multiple nodes. For receiving an interrupt, the state machine accepts an interrupt from another node and stores it in the receive queue, notifying the interrupt source that the interrupt has been accepted before its is placed on the node bus. The interrupt has the second form suitable for transmission across the network. The interrupt controller takes the interrupt from the receive queue and puts it in the first form suitable for transmission on the bus.
摘要:
A multiple-stage pipeline for transaction conversion is disclosed. A method is disclosed that converts a transaction into a set of concurrently performable actions. In a first pipeline stage, the transaction is decoded into an internal protocol evaluation (PE) command, such as by utilizing a look-up table (LUT). In a second pipeline stage, an entry within a PE random access memory (RAM) is selected, based on the internal PE command. This may be accomplished by converting the internal PE command into a PE RAM base address and an associated qualifier thereof. In a third pipeline stage, the entry within the PE RAM is converted to the set of concurrently performable actions, such as based on the PE RAM base address and its associate qualifier.
摘要:
A method of invalidating shared cache lines such as on a sharing list by issuing an invalidate acknowledgement before actually invalidating a cache line. The method is useful in multiprocessor systems such as a distributed shared memory (DSM) or non-uniform memory access (NUMA) machines that include a number of interconnected processor nodes each having local memory and caches that store copies of the same data. In such a multiprocessor system using the Scalable Content Interface (SCI) protocol, an invalidate request is sent from the head node on the sharing list to a succeeding node on the list. In response to the invalidate request, the succeeding node issues an invalidate acknowledgement before the cache line is actually invalidated. After issuing the invalidate acknowledgement, the succeeding node initiates invalidation of the cache line. The invalidate acknowledgement can take the form of a response to the head node or a forwarding of the invalidate request to the next succeeding node on the list. To maintain processor consistency, a flag is set each time an invalidate acknowledgement is sent. The flag is cleared after the invalidation of the cache line is completed. Cacheable transactions received at the succeeding node while a flag is set are delayed until the flag is cleared.
摘要:
This disclosure describes systems, devices, methods and computer readable media for enhanced network communication for use in higher performance applications including storage, high performance computing (HPC) and Ethernet-based fabric interconnects. In some embodiments, a network controller may include a transmitter circuit configured to transmit packets on a plurality of virtual lanes (VLs), the VLs associated with a defined VL priority and an allocated share of network bandwidth. The network controller may also include a bandwidth monitor module configured to measure bandwidth consumed by the packets and an arbiter module configured to adjust the VL priority based on a comparison of the measured bandwidth to the allocated share of network bandwidth. The transmitter circuit may be further configured to transmit the packets based on the adjusted VL priority.
摘要:
A method and apparatus for providing cache coherence in a multiprocessor system which is configured into two or more nodes with memory local to each node and a tag and address crossbar system and a data crossbar system which interconnects all nodes. The disclosure is applicable to multiprocessor computer systems which utilize system memory distributed over more than one node and snooping of data states in each node which utilizes memory local to that node. Global snooping is used to provide a single point of serialization of data tags. A central crossbar controller examines cache state tags of a given address line for all nodes simultaneously and issues an appropriate reply back to a node requesting data while generating other data requests to any other node in the system for the purpose of maintaining cache coherence and supplying the requested data. The system utilizes memory local to each node by dividing such memory into local and remote categories which are mutually exclusive for any given cache line. The disclosure provides support for a third level remote cache for each node.
摘要:
Removing building blocks from partitions to which they have been bound is disclosed. A building block of a platform is removed from a partition of the platform by first halting activity by the partition on the building block. A first partition identifier of the building block indicates the partition of the building block. The building block joined the partition in a masterless manner. The resources of the building block are withdrawn from the partition, and the building block is deauthorized from the platform.
摘要:
A method and apparatus for maintaining processor consistency in a multiprocessor computer such as a multinode computer system are disclosed. A processor proceeds with write operations before its previous write operations complete, while processor consistency is maintained. A write operation begins with a request by the processor to invalidate copies of the data stored in other nodes. This current invalidate request is queued while acknowledging to the processor that the request is complete even though it has not actually completed. The processor proceeds to complete the write operation by changing the data. It can then execute subsequent operations, including other write operations. The queued request, however, is not transmitted to other nodes in the computer until all previous invalidate requests by the processor are complete. This ensures that the current invalidate request will not pass a previous invalidate request. The invalidate requests are added and removed from a processor's outstanding invalidate list as they arise and are completed. An invalidate request is completed by notifying the nodes in a linked list related to the current invalidate request that data shared by the node is now invalid.
摘要:
This disclosure describes systems, devices, methods and computer readable media for enhanced network communication for use in higher performance applications including storage, high performance computing (HPC) and Ethernet-based fabric interconnects. In some embodiments, a network controller may include a transmitter circuit configured to transmit packets on a plurality of virtual lanes (VLs), the VLs associated with a defined VL priority and an allocated share of network bandwidth. The network controller may also include a bandwidth monitor module configured to measure bandwidth consumed by the packets and an arbiter module configured to adjust the VL priority based on a comparison of the measured bandwidth to the allocated share of network bandwidth. The transmitter circuit may be further configured to transmit the packets based on the adjusted VL priority.
摘要:
Methods, apparatus, and systems for implementing hierarchical and lossless packet preemption and interleaving to reduce latency jitter in flow-controller packet-based networks. Fabric packets are divided into a plurality of data units, with data units for different fabric packets buffered in separate buffers. Data units are pulled from the buffers and added to a transmit stream in which groups of data units are interleaved. Upon receipt by a receiver, the groups of data units are separated out and buffered in separate buffers under which data units for the same fabric packets are grouped together. In one aspect, each buffer is associated with a respective virtual lane (VL), and the fabric packets are effectively transferred over fabric links using virtual lanes. VLs may have different levels of priority under which data units for fabric packets in higher-priority VLs may preempt fabric packets in lower-priority VLs. By transferring data units rather than entire packets, transmission of a packet can be temporarily paused in favor of a higher-priority packet. Multiple levels of preemption and interleaving in a nested manner are supported.