Hewlett-packard Development Company, L.p.

Hewlett Packard Enterprise Development LP

Hewlett-packard Company

Shawn Kenneth Walker

Derek Alan Sherlock

Terry L Lyon

Dean A Mulla

Donald Charles Soltis, Jr

Paolo Faraboschi

Gary Belgrave Gostin

Eric R Delano

Rohit Bhatia

Karl P Brummel

Blaine Stackhouse

James R Callister

Christopher Shawn Kroeger

Mark M Gibson

A memory access system may include a first memory address translator, a second memory address translator and a mapping entry invalidator. The first memory address translator translates a first virtual address in a first protocol of a memory access request to a second virtual address in a second protocol and tracks memory access request completions. The second memory address translator is to translate the second virtual address to a physical address of a memory. The mapping entry invalidator requests invalidation of a first mapping entry of the first mapping address translator requests invalidation of a second mapping entry of the second memory address translator corresponding to the first mapping entry following invalidation of the first mapping entry and based upon the tracked memory access request completions.

Mapping entry invalidation

A system comprises a processor, a memory fabric, and a fabric bridge coupled to the memory fabric and the processor. The fabric bridge may receive, from the processor a first eviction request comprising first eviction data, transmit, to the processor, a message indicating the fabric bridge has accepted the first eviction request, transmit a first write comprising the first eviction data to the fabric, receive, from the processor, a second eviction request comprising second eviction data, and transmit a second write comprising the second eviction data to the fabric. Responsive to transmitting the second write request, the fabric bridge may transmit, to the processor, a message indicating the fabric bridge accepted the second eviction request, determine that the first write and the second write have persisted, and transmit, to the processor, a notification to the processor responsive to determining that the first write and the second write have persisted.

Issuing write requests to a fabric

In some examples, a controller includes a counter to track errors associated with a group of memory access operations, and processing logic to detect an error associated with the group of memory access operations, determine whether the detected error causes an error state change of the group of memory access operations, and cause advancing of the counter responsive to determining that the detected error causes the error state change of the group of memory access operations.

Tracking errors associated with memory access operations

A PCIe (Peripheral Component Interconnect Express) protocol converter for connection to a central processing unit (CPU) node having a root complex, a CPU memory fabric and CPU memory may include independent PCIe links, a fabric interface and a fabric switch connected to the fabric interface. Each of the links may include an endpoint for connection to the root complex. The fabric switch is connected to the fabric interface of each of the links and is connectable to a remote node. The fabric switch transmits writes of a single write request from the remote node across both links. Each fabric interface is to transmit an acknowledgment to the remote node in response to a write of the writes becoming observable at the CPU node hi Michael, hi Michael,.

PCIe write request acknowledgment

An apparatus for assisting a flush of a cache is described herein. The apparatus comprises processing element. The processing element is to probe a cache line at an offset address and write the cache line at the offset address to a non-volatile memory in response to a flush instruction at a first address.

Hardware flush assist

Systems, methodologies, media, and other embodiments associated with mitigating the effects of context switch cache and TLB misses are described. One exemplary system embodiment includes a processor configured to run a multiprocessing, virtual memory operating system. The processor may be operably connected to a memory and may include a cache and a translation lookaside buffer (TLB) configured to store TLB entries. The exemplary system may include a context control logic configured to selectively copy data from the TLB to the data store for a first process being swapped out of the processor and to selectively copy data from the data store to the TLB for a second process being swapped into to the processor.

Mitigating context switch cache miss penalty

A cache memory system capable of adaptively accommodating various memory line sizes comprises cache memory and cache logic. The cache memory has sets of ways. The cache logic is configured to request a memory line in response to a cache miss, and the memory line represents a portion of a way line. The cache logic is configured to select one of the ways based on which portion of the way line is represented by the memory line. The cache logic is further configured to store the memory line in the selected way.

Cache memory system and method capable of adaptively accommodating various memory line sizes

A method, and a corresponding apparatus, mask error detection and correction latency during multilevel cache transfers. The method includes the steps of transferring error protection encoded data lines from a first cache, checking the error protection encoded data lines for errors, wherein the checking is completed after the transferring begins, receiving the error protection encoded data lines in a second cache, and upon detecting an error in a data line, preventing further transfer of the data line from the second cache.

Masking error detection/correction latency in multilevel cache transfers

A source cache transfers data to an intermediate cache along a data connection. The intermediate cache is provided between the source cache and a target, and includes a memory array. The source cache may also transfer data to the target along the data connection while bypassing the memory array of the intermediate cache.

Cache connection with bypassing feature

A method and apparatus consolidate ports on a unified cache. The apparatus uses plurality of access connections with a single port of a memory. The apparatus comprises multiplexor and a logic circuit. The multiplexor is connected to the plurality of access connections. The multiplexor has a control input and a memory connection. The logic circuit produces an output signal tied to the control input. In another form, the apparatus comprises means for selectively coupling a single one of the plurality of access connections to the memory, and a means for controlling the means for coupling. Preferably, the plurality of access connections comprise a data connection and an instruction connection, and the memory is cache memory. The method uses a single memory access connection for a plurality of access types. The method accepts one or more memory access requests on one or more respective ones of a plurality of connections. If there are memory access requests simultaneously active on two or more of the plurality of connections, then the method selects one of the simultaneously active connections and connects the selected connection to the single memory access connection.

Unified cache port consolidation

Methods and apparatus mask the latency of error detection and/or error correction applied to data transferred between a first memory and a second memory. The method comprises determining whether there is an error in a data unit in the first memory; transferring data based on the data unit from the first memory to a second memory, wherein the transferring step commences before completion of the determining step; and disabling at least part of the second memory if the determining step detects an error in the data unit. The disabling step may be accomplished, for example, by disabling the buffering of an address of the data unit or stalling the second memory.

Disclosed is a device and method for testing of a program or a design of an electronic device comprising digital logic circuitry. The method comprises testing the design of software or an electronic device and injecting, after initiation of the testing step, a predetermined error pattern into a value operated upon by the design of the digital logic circuitry. In a preferred embodiment, the software is a simulation of the design of a processor having a cache with error detection and/or correction circuitry. A triggering condition is preferably a cache hit, in response to which a detectable error is injected into the cache. The simulated operations of the model are observed to determine whether the injected error is detected, as should happen if the processor's error detection circuitry has been designed properly. In another respect, the invention is an apparatus, or computer software embedded on a computer readable medium, for testing a program comprising an error detector. The apparatus or software comprises the program, an error injector module connected to the program; and a checker module connected to the program. The checker module is capable of determining whether the program responds appropriately to an error dynamically produced by the error injector module during execution of the program. By injecting errors dynamically the invention easily facilitates precisely focused testing at any time during simulated operation regardless of initialization conditions.

Growing community of inventors

Fort Collins, CO, United States of America

Shawn Kenneth Walker