Abstract: A data processor includes provides memory commands to a memory channel according to predetermined criteria. The data processor includes a first error code generation circuit, a second error code generation circuit, and a queue. The first error code generation circuit generates a first type of error code in response to data of a write request. The second error code generation circuit generates a second type of error code for the write request, the second type of error code different from the first type of error code. The queue is coupled to the first error code generation circuit and to the second error code generation circuit, for provides write commands to an interface, the write commands including the data, the first type of error code, and the second type of error code.

Abstract: A method includes reserving memory capacity in a first memory device as patch memory region for backing faulted memory, receiving a memory error indication indicating an uncorrectable error in a faulted segment in a second memory device and, in response to the memory error indication, associating in a remapping table the faulted segment with a patch segment in the patch memory region. The faulted segment is smaller than a memory page size of the second memory device. The method also includes, in response to receiving a memory access request directed to the faulted memory segment, servicing the memory access request from the patch segment by querying the remapping table to determine a patch segment address corresponding to a requested memory address, where the patch segment address identifies the location of the patch segment, and based on the patch segment address, performing the requested memory access at the patch segment.

Abstract: Error handling for resilient software includes: receiving data indicating a region of resilient memory; detecting an error associated with a region of memory; and preventing raising an exception for the error in response to the region of memory falling within the region of resilient memory by preventing the region of memory as being identified as including the error.

Abstract: A data processing system includes a memory channel, a memory coupled to the memory channel, and a data processor. The data processor is coupled to the memory channel and accesses the memory over the memory channel using a packet structure defining a plurality of commands and having corresponding address bits, data bits, and user bits. The data processor communicates with the memory over the memory channel using a first type of error code. In response to a write access request, the data processor calculates a different, second type of error code and appends each bit of the second type of error code as a corresponding one of the user bits. The memory stores the user bits in the memory in response to a write command, and transfers the user bits to the data processor in a read response packet in response to a read command.

Abstract: A memory controller includes a command queue, a memory interface queue, and a non-volatile error reporting circuit. The command queue receives memory access commands including volatile reads, volatile writes, non-volatile reads, and non-volatile writes, and an output. The memory interface queue has an input coupled to the output of the command queue, and an output for coupling to a non-volatile storage class memory (SCM) module. The non-volatile error reporting circuit identifies error conditions associated with the non-volatile SCM module and maps the error conditions from a first number of possible error conditions associated with the non-volatile SCM module to a second, smaller number of virtual error types for reporting to an error monitoring module of a host operating system, the mapping based at least on a classification that the error condition will or will not have a deleterious effect on an executable process running on the host operating system.

Abstract: Error handling for resilient software includes: receiving data indicating a region of resilient memory; detecting an error associated with a region of memory; and preventing raising an exception for the error in response to the region of memory falling within the region of resilient memory by preventing the region of memory as being identified as including the error.

Abstract: A method includes reserving memory capacity in a first memory device as patch memory region for backing faulted memory, receiving a memory error indication indicating an uncorrectable error in a faulted segment in a second memory device and, in response to the memory error indication, associating in a remapping table the faulted segment with a patch segment in the patch memory region. The faulted segment is smaller than a memory page size of the second memory device. The method also includes, in response to receiving a memory access request directed to the faulted memory segment, servicing the memory access request from the patch segment by querying the remapping table to determine a patch segment address corresponding to a requested memory address, where the patch segment address identifies the location of the patch segment, and based on the patch segment address, performing the requested memory access at the patch segment.

Abstract: Selecting an error correction code type for a memory device includes: selecting, by the memory device in dependence upon predefined selection criteria, one of a plurality of error correction code types and carrying out memory access requests utilizing the selected error correction code type.

Abstract: A data processing system includes a memory channel, a memory coupled to the memory channel, and a data processor. The data processor is coupled to the memory channel and accesses the memory over the memory channel using a packet structure defining a plurality of commands and having corresponding address bits, data bits, and user bits. The data processor communicates with the memory over the memory channel using a first type of error code. In response to a write access request, the data processor calculates a different, second type of error code and appends each bit of the second type of error code as a corresponding one of the user bits. The memory stores the user bits in the memory in response to a write command, and transfers the user bits to the data processor in a read response packet in response to a read command.

Abstract: Described herein are a method and apparatus for memory vulnerability prediction. A memory vulnerability predictor predicts the reliability of a memory region when it is first accessed, based on past program history. The memory vulnerability predictor uses a table to store reliability predictions and predicts reliability needs of a new memory region. A memory management module uses the reliability information to make decisions, (such as to guide memory placement policies in a heterogeneous memory system).

Abstract: Techniques for selecting one of a plurality of heterogeneous memory units for placement of blocks of data (e.g., memory pages), based on both reliability and performance, are disclosed. A “cost” for each data block/memory unit combination is determined, based on the frequency of access of the data block, the latency of the memory unit, and, optionally, an architectural vulnerability factor (which represents the level of exposure of a particular memory data value to memory faults such as bit flips). A memory unit is selected for the data block for which the determined cost is the lowest, out of all memory units considered, and the data block is placed into that memory unit.

Abstract: Described herein are waterfall counters and an application to architectural vulnerability factor (AVF) estimation. Waterfall counters count events that are generated at event generation logic. The waterfall counters are a combination of small, fast counters local to the event generation logic, and larger, global counters in fast memory. The local counters can be saturation or oscillation counters. When a local counter is saturated or evicted, the value from the local counter is added to the global counter. This addition can be done using logic local to the local or global counter. The waterfall counters provide a full-accuracy event count without the high bandwidth that is needed to maintain the global counters. An AVF estimation can be determined based on ratios from counts of read events, write events, and total events using the waterfall counters.

Abstract: Described herein are a method and apparatus for memory vulnerability prediction. A memory vulnerability predictor predicts the reliability of a memory region when it is first accessed, based on past program history. The memory vulnerability predictor uses a table to store reliability predictions and predicts reliability needs of a new memory region. A memory management module uses the reliability information to make decisions, (such as to guide memory placement policies in a heterogeneous memory system).

Abstract: Methods and apparatus presented herein provide distributed checkpointing in a multi-node system, such as a network of servers in a data center. When checkpointing of application state data is needed in a node, the methods and apparatus determine whether checkpoint memory space is available in the node for checkpointing the application state data. If not enough checkpoint memory space is available in the node, the methods and apparatus request and find additional checkpoint memory space from other nodes in the system. In this manner, the methods and apparatus can checkpoint the application state data into available checkpoint memory spaces distributed among a plurality of nodes. This allows for high bandwidth and low latency checkpointing operations in the multi-node system.

Abstract: Described herein are waterfall counters and an application to architectural vulnerability factor (AVF) estimation. Waterfall counters count events that are generated at event generation logic. The waterfall counters are a combination of small, fast counters local to the event generation logic, and larger, global counters in fast memory. The local counters can be saturation or oscillation counters. When a local counter is saturated or evicted, the value from the local counter is added to the global counter. This addition can be done using logic local to the local or global counter. The waterfall counters provide a full-accuracy event count without the high bandwidth that is needed to maintain the global counters. An AVF estimation can be determined based on ratios from counts of read events, write events, and total events using the waterfall counters.

Abstract: Methods and apparatus presented herein provide distributed checkpointing in a multi-node system, such as a network of servers in a data center. When checkpointing of application state data is needed in a node, the methods and apparatus determine whether checkpoint memory space is available in the node for checkpointing the application state data. If not enough checkpoint memory space is available in the node, the methods and apparatus request and find additional checkpoint memory space from other nodes in the system. In this manner, the methods and apparatus can checkpoint the application state data into available checkpoint memory spaces distributed among a plurality of nodes. This allows for high bandwidth and low latency checkpointing operations in the multi-node system.

Abstract: Techniques for selecting one of a plurality of heterogeneous memory units for placement of blocks of data (e.g., memory pages), based on both reliability and performance, are disclosed. A “cost” for each data block/memory unit combination is determined, based on the frequency of access of the data block, the latency of the memory unit, and, optionally, an architectural vulnerability factor (which represents the level of exposure of a particular memory data value to memory faults such as bit flips). A memory unit is selected for the data block for which the determined cost is the lowest, out of all memory units considered, and the data block is placed into that memory unit.

Abstract: In the described embodiments, a processor core (e.g., a GPU core) receives a section of program code to be executed in a transaction from another entity in a computing device. The processor core sends the section of program code to one or more compute units in the processor core to be executed in a first transaction and concurrently executed in a second transaction, thereby creating a “redundant transaction pair.” When the first transaction and the second transaction are completed, the processor core compares a read-set of the first transaction to a read-set of the second transaction and compares a write-set of the first transaction to a write-set of the second transaction. When the read-sets and the write-sets match and no transactional error condition has occurred, the processor core allows results from the first transaction to be committed to an architectural state of the computing device.

Abstract: A memory subsystem employs spare memory cells external to one or more memory devices. In some embodiments, a processing system uses the spare memory cells to replace individual selected cells at the protected memory, whereby the selected cells are replaced on a cell-by-cell basis, rather than exclusively on a row-by-row, column-by-column, or block-by-block basis. This allows faulty memory cells to be replaced efficiently, thereby improving memory reliability and manufacturing yields, without requiring large blocks of spare memory cells.

Abstract: A system, method and computer program product to execute a first and a second work-item, and compare the signature variable of the first work-item to the signature variable of the second work-item. The first and the second work-items are mapped to an identifier via software. This mapping ensures that the first and second work-items execute exactly the same data for exactly the same code without changes to the underlying hardware. By executing the first and second work-items independently, the underlying computation of the first and second work-item can be verified. Moreover, system performance is not substantially affected because the execution results of the first and second work-items are compared only at specified comparison points.