Abstract: Machine learning is utilized to analyze respective execution times of a plurality of tasks in a job performed in a distributed computing system to determine that a subset of the plurality of tasks are straggler tasks in the job, where the distributed computing system includes a plurality of computing devices. A supervised machine-learning algorithm is performed using a set of inputs including performance attributes of the plurality of tasks, where the supervised machine learning algorithm uses labels generated from determination of the set of straggler tasks, the performance attributes include respective attributes of the plurality of tasks observed during performance of the job, and applying the supervised learning algorithm results in identification of a set of rules defining conditions, based on the performance attributes of the plurality of tasks, indicative of which tasks will be straggler tasks in a job. Rule data is generated to describe the set of rules.

Abstract: An apparatus comprises processing circuitry to execute instructions from one or more of a plurality of execution contexts each associated with a respective execution context identifier; a cache; and a speculative buffer. Control circuitry controls allocation of data to the cache and the speculative buffer. A speculative entry, for which allocation is caused by a speculative memory access associated with a given execution context, is allocated to the speculative buffer instead of to the cache while the speculatively executed memory access instruction remains speculative. The speculative entry specifies, as a tagged execution context identifier, the execution context identifier associated with the given execution context. Presence of the speculative entry in the speculative buffer is prevented from being observable to execution contexts other than the execution context identified by the tagged execution context identifier.

Abstract: Apparatuses, methods, programs, and complex number processing instructions are provided to support vector processing operations on input data vectors comprising a plurality of input data items at respective positions in the input data vectors. In response to the instructions at least one first set of data items is extracted from alternating positions in a first source register and at least one second set of data items is extracted from alternating positions in the second source register, wherein consecutive data items in the first and second source registers comprise alternating real and imaginary components of respective sets of complex numbers. A result set of complex number components is generated using the two sets of data items as operands, and the result set of complex number components is one of a real part and an imaginary part of a complex number result of the complex number operation applied to the two sets of complex numbers.

Abstract: Aspects of the present disclosure relate to an apparatus comprising decode circuitry to receive an instruction and identify the received instruction as a load instruction, and prediction circuitry to predict, based on a prediction scheme, a target address of the load instruction, and trigger a speculative memory access in respect of the predicted target address.

Abstract: A computer-implemented method includes executing, using a computer, a process including a main thread that receives a layout file. The layout file includes a first plurality of tags and compressed information blocks. Each tag of the first plurality is associated with a compressed information block. The method further includes decompressing the compressed information blocks using sub-threads and thereby obtaining decompressed information blocks. The sub-threads are created by the main thread, and each sub-thread corresponds to a compressed information block. The decompressed information blocks are combined into decompressed layout information. The decompressed file is partitioned and each partition is provided to a node of a distributed computing system for performing layout correction.

Abstract: A cache system having cache sets, and the cache sets having a first cache set configured to provide a first physical output upon a cache hit and a second cache set configured to provide a second physical output upon a cache hit. The cache system also has a control register and a mapping circuit coupled to the control register to map respective physical outputs of the cache sets to a first logical cache and a second logical cache according to a state of the control register. The first logical cache can be a normal or main cache for non-speculative executions by a processor and the second logical cache can be a shadow cache for speculative executions by the processor.

Abstract: The disclosure discloses a method for defending control flow attacks. When a data processor gives a response to an interrupt routine, a return address and a binary key are input to an encryption circuit to be encrypted to obtain an encrypted return address, and the obtained encrypted return address is synchronously written into a stack of the data processor and an built-in register bank; when the response given to the interrupt routine by the data processor is finished, the encrypted return address is read from the tack of the data processor and the built-in register bank; afterwards, the two encrypted return addresses are decrypted by first and second decryption circuits respectively to obtain two decrypted return addresses; and the two decrypted return addresses are compared to draw a conclusion whether the data process suffers from a control flow attack, and data processor determines to continue or terminate the routine accordingly.

Abstract: This control system is provided with a plurality of slave devices and controllers. The controller is connected to one end of a field bus which includes the plurality of slave devices that is linearly connected, and the controller is connected to the other end of the field bus through a communication cable. The controllers are provided with a CPU and a transception part. One of the controllers generates a control frame with the CPU and transmits this from the transception part, and the other of the controllers performs a loop communication of the control frame by the transception part.

Abstract: An apparatus to facilitate processing of a sparse matrix is disclosed. The apparatus includes a plurality of processing units each comprising one or more processing elements, including logic to read operands, a multiplication unit to multiply two or more operands and a scheduler to identify operands having a zero value and prevent scheduling of the operands having the zero value at the multiplication unit.

Abstract: An apparatus that includes a program controller to fetch and issue instructions is described. The apparatus includes an execution lane having at least one execution unit to execute the instructions. The execution lane is part of an execution lane array that is coupled to a two dimensional shift register array structure, wherein, execution lane s of the execution lane array are located at respective array locations and are coupled to dedicated registers at same respective array locations in the two-dimensional shift register array.

Abstract: Systems and methods are disclosures for scheduling code in a multiprocessor system. Code is portioned into code blocks by a compiler. The compiler schedules execution of code blocks in nodes. The nodes are connected in a directed acyclical graph with a top node, terminal node and a plurality of intermediate nodes. Execution of the top node is initiated by the compiler. After executing at least one instance of the top node, an instruction in the code block indicates to the scheduler to initiate at least one intermediary node. The scheduler schedules a thread for execution of the intermediary node. The data for the nodes resides in a plurality of data buffers; the index to the data buffer is stored in a command buffer.

Abstract: A hardware monitor circuit includes an electronic control circuit coupled to a processing unit. The electronic control circuit generates multi-bit protection codes and directs operations of the hardware monitor circuit. A bus interface is coupled to an address bus of the processing unit, and the bus interface passes signals associated with a stack structure of the processing unit. The stack structure is arranged to store the multi-bit protection codes in an internal memory coupled to the processing unit. Comparators in the hardware monitor circuit are arranged to accept values from the internal memory and gating logic coupled to the comparators is arranged to generate an error signal when it detects that an address on the address bus read via the bus interface is equal to an address stored in the internal memory. Upon generating the error signal, the processing unit is placed in a secure mode.

Abstract: Portions of configuration state registers in-memory. An instruction is obtained, and a determination is made that the instruction accesses a configuration state register. A portion of the configuration state register is in-memory and another portion of the configuration state register is in-processor. Processing associated with the configuration state register is performed. The performing processing is based on a type of access and whether the portion or the other portion is being accessed.

Abstract: Dynamic generation and implementation of assignment mappings of data items in large data files to distributed processors to achieve objectives such as reduced overall processing time like. Any appropriate key (e.g., character string) can be identified or obtained for each data item in a data file and the file can be segmented into sequential data blocks, where each data block includes a set of data items. The data items in each of a first plurality of the blocks (e.g., sampled block set) may be initially sorted into one of a plurality of key ranges of a search space (each corresponding to a different respective processor) and analyses conducted on the data items totals in each key range. The key range boundaries can be adjusted by accounting for uncertainty in the sample estimates to more evenly distribute data items from all blocks sent to each processor and thereby achieve the objective.

Abstract: Reusing executed, flushed instructions after an instruction pipeline flush in response to a hazard in a processor to reduce instruction re-execution is disclosed. An instruction processing circuit detects fetched performance degrading instructions (PDIs) in an instruction pipeline that may cause a flushing of the instruction pipeline. In response to detecting a PDI, the instruction processing circuit is configured to store the PDI and/or its successor younger instructions in a pipeline execution refill circuit. In response to successful execution of such PDI and/or younger instructions, information about their input value(s) and produced output value(s) when executed are captured in the pipeline execution refill circuit.

Abstract: Representative apparatus, method, and system embodiments are disclosed for a self-scheduling processor which also provides additional functionality. Representative embodiments include a self-scheduling processor, comprising: a processor core adapted to execute a received instruction; and a core control circuit adapted to automatically schedule an instruction for execution by the processor core in response to a received work descriptor data packet. In another embodiment, the core control circuit is also adapted to schedule a fiber create instruction for execution by the processor core, to reserve a predetermined amount of memory space in a thread control memory to store return arguments, and to generate one or more work descriptor data packets to another processor or hybrid threading fabric circuit for execution of a corresponding plurality of execution threads. Event processing, data path management, system calls, memory requests, and other new instructions are also disclosed.

Abstract: A trace module has monitoring circuitry for monitoring processing of instructions by processing circuitry, and trace output circuitry for outputting a sequence of elements indicative of outcomes of the processing of instructions by the processing circuitry. The trace module supports output of a commit window move element indicating that a commit window, representing a portion of the trace stream comprising at least one speculative element representing at least one speculatively executed instruction, should move while the oldest remaining speculative element of the trace stream remains uncommitted. This can be useful for tracing of transactional memory functionality within program code.

Abstract: Techniques related to executing a plurality of instructions by a processor comprising receiving a first instruction for execution on an instruction execution pipeline, wherein the instruction execution pipeline is in a first execution mode, beginning execution of the first instruction on the instruction execution pipeline, receiving an execution mode instruction to switch the instruction execution pipeline to a second execution mode, switching the instruction execution pipeline to the second execution mode based on the received execution mode instruction, annulling the first instruction based on the execution mode instruction, receiving a second instruction for execution on the instruction execution pipeline, the second instruction, and executing the second instruction.

Abstract: The disclosed technology is generally directed to protection against unauthorized code. In one example of the technology, a read request to a restricted region of memory is detected. The read request is associated with a first processor. In response to detecting the read request to the restricted region of memory, a data value that causes an exception in response to execution by the first processor is provided.

Abstract: Implementations of using tiles for caching are detailed In some implementations, an instruction execution circuitry executes one or more instructions, a register state cache coupled to the instruction execution circuitry holds thread register state in a plurality of registers, and backing storage pointer storage stores a backing storage pointer, wherein the backing storage pointer is to reference a state backing storage area in external memory to store the thread register state stored in the register state cache.

Abstract: Embodiments of an invention for protecting supervisor mode information are disclosed. In one embodiment, an apparatus includes a storage location, instruction hardware, execution hardware, and control logic. The storage location is to store an indicator to enable supervisor mode information protection. The instruction hardware is to receive an instruction to access supervisor mode information. The execution hardware is to execute the instruction. The control logic is to prevent execution of the instruction if supervisor mode information protection is enabled and a current privilege level is less privileged than a supervisor mode.

Abstract: A processor includes a load/store unit that includes one or more load pipelines and one or more store pipelines. Load operations may be issued into the load pipelines out of order with respect to older store operations. If a load operation is executed out or order with an older store operation that writes one or more bytes read by the load operation, and if the store operation is issued shortly after the load operation, such that the load operation is still in the load pipeline when the store operation is issued, some cases of flushing may be converted to replays by detecting the ordering violation while the load operation is still in the load pipeline.

Abstract: A first memory request including a first virtual address is received. An entry in memory is accessed. The entry is selected using information associated with the first memory request, and includes at least a portion of a second virtual address (first data) and at least a portion of a third virtual address (second data). The difference between the first data and the second data is compared with differences between a corresponding portion of the first virtual address and the first data and the second data respectively. When a result of the comparison is true, then a fourth virtual address is determined by adding the difference between the first data and the second data to the first virtual address, and then data at the fourth virtual address is prefetched into the cache.

Abstract: Systems and methods are disclosed for performing wide memory operations for a wide data cache line. In some examples of the disclosed technology, a processor having two or more execution lanes includes a data cache coupled to memory, a wide memory load circuit that concurrently loads two or more words from a cache line of the data cache, and a writeback circuit situated to send a respective word of the concurrently-loaded words to a selected execution lane of the processor, either into an operand buffer or bypassing the operand buffer. In some examples, a sharding circuit is provided that allows bitwise, byte-wise, and/or word-wise manipulation of memory operation data. In some examples, wide cache loads allows for concurrent execution of plural execution lanes of the processor.

Abstract: Disclosed aspects relate to window management in a stream computing environment. A set of computing resources may be detected with respect to the stream computing environment. Based on the set of computing resources, a set of window configurations in the stream computing environment may be determined. In response to determining the set of window configurations in the stream computing environment, the set of window configurations may be established in the stream computing environment.

Abstract: In one embodiment, an apparatus includes a memory access circuit to receive memory access instructions and provide at least some of the memory access instructions to a memory subsystem for execution. The memory access circuit may have a conversion circuit to convert the first memory access instruction to a first subline memory access instruction, e.g., based at least in part on an access history for a first memory access instruction. Other embodiments are described and claimed.

Abstract: In a decode stage of hardware processor pipeline, one particular instruction of a plurality of instructions is decoded. It is determined that the particular instruction requires a memory access. Responsive to such determination, it is predicted whether the memory access will result in a cache miss. The predicting in turn includes accessing one of a plurality of entries in a pattern history table stored as a hardware table in the decode stage. The accessing is based, at least in part, upon at least a most recent entry in a global history buffer. The pattern history table stores a plurality of predictions. The global history buffer stores actual results of previous memory accesses as one of cache hits and cache misses.

Abstract: Systems, apparatuses, and methods related to bit string compression are described. A method for bit string compression can include determining that a particular operation is to be performed using a bit string formatted according to a universal number format or a posit format to alter a bit width associated with the bit string from a first bit width to a second bit width and performing a compression operation on a bit string formatted according to a universal number format or a posit format to alter a bit width associated with the bit string from a first bit width to a second bit width. The method can further include writing the bit string having the second bit width to a first register, performing an arithmetic operation or a logical operation, or both using the bit string having the second bit string width, and monitoring a quantity of bits of a result of the operation.

Abstract: In example implementations, an apparatus is provided. The apparatus includes a context switch block, a processor performance state block, and a task execution block. The context switch block is to perform a context switch. The processor performance state block is to load a processor with a processor performance state stored in a context information associated with a task. The task execution block is to execute the task with the processor operating at the processor performance state loaded from the context information.

Abstract: Systems and methods of enabling virtual calls in a single instruction multiple data (SIMD) environment may involve detecting a virtual call of a function and using a single dispatch of the function to invoke the virtual call for two or more channels of the virtual call. In one example, it is determined that the two or more channels share a common target address and a single dispatch of the function is conducted with respect to the common target address. The process may be iterated for additional channels of the virtual call that share a common target address.

Abstract: A computer system, processor, and method for processing information is disclosed that includes a Dispatch Unit for dispatching instructions; an Issue Queue for receiving instructions dispatched from the Dispatch Unit; and a queue for receiving instructions issued from the Issue Queue, the queue having a plurality of entry locations for storing data. In an embodiment instructions are dispatched with a virtual indicator, and the virtual indicator is set to a first mode for instructions dispatched where an entry location is available, and to a second mode where an entry location is not available, in the queue to receive the dispatched instruction. In addition to virtual tagging dispatched instructions, a system, processor, and method are disclosed for regional partitioning of queues, region based deallocation of queue entries, and circular thread based assignment of queue entries.

Abstract: A redundancy method of a three-dimensional laminated memory includes receiving, by first, second and third processors, a command for data operation, transmitting and receiving, by each of the second and third processors, data through dedicated data buses in order to perform the data operation, receiving, by the first processor, operation result values of the second and third processors from a main memory, comparing, by a result value comparator of the first processor, the operation result values of the first, second and third processors, and outputting, by the result value comparator, operation result values in correspondence with the result of comparison.

Abstract: One example includes performing a VM restore instance type discovery process, creating a test VM with a VM restore instance type matching a VM restore instance type identified during discovery, using the test VM to create a test restore VM at a cloud storage site, restoring the test VM at the cloud storage site using the test restore VM, generating a 4-D baseline vector based on the restoration of the test VM, the 4-D baseline vector identifying a particular VM restore instance type, generating a 5-D vector based on the 4-D baseline vector, ranking the 5-D vector relative to other 5-D vectors, the 5-D vectors identifying the same production site VM, and restoring, at the cloud storage site, the production site VM identified in the 5-D vectors, the production site VM restored at the cloud storage site has a VM restore instance type identified in the highest ranked 5-D vector.

Abstract: A computer system includes a processor, main memory, and controller. The processor includes a plurality of hardware threads configured to execute a plurality of software threads. The main memory includes a first register table configured to contain a current set of architected registers for the currently running software threads. The controller is configured to change a first number of the architected registers assigned to a given one of the software threads to a second number of architected registers when a result of monitoring current usage of the registers by the software threads indicates that the change will improve performance of the computer system. The processor includes a second register table configured to contain a subset of the architected registers and a mapping table for each software thread indicating whether the architected registers referenced by the corresponding software thread are located in the first register table or the second register table.

Abstract: Various systems and methods for virtual CPU consolidation to avoid physical CPU contention between virtual machines are described herein. A processor system that includes multiple physical processors (PCPUs) includes a first virtual machine (VM) that includes multiple first virtual processors (VCPUs); a second VM that includes multiple second VCPUs; and a virtual machine monitor (VMM) to map individual ones of the first VCPUs to run on at least one of, individual PCPUs of a first subset of the PCPUs and individual PCPUs of a set of PCPUs that includes the first subset of the PCPUs and a second subset of the PCPUs, based at least in part upon compute capacity of the first subset of the PCPUs to run the first VCPUs, and to map individual ones of the second VCPUs to run on individual ones of the second subset of the PCPUs.

Abstract: Disclosed are a method, a device, and a single-tasking system for implementing multi-tasking in a single-tasking system. The method includes: performing a master task; allocating a hardware timer to a slave task on a central processing unit (CPU); configuring an interrupt period of the hardware timer; and generating, by the hardware timer, a hardware interrupt periodically based on the interrupt period to trigger the performance of the slave task. Therefore, independent and concurrent execution of the master task and slave task can be achieved in a single-tasking system, without the need to add an unwieldy multitasking scheduling framework to the operating system. Furthermore, the slave task is executed only when the hardware timer generates hardware interrupts, so less system resources will be consumed and the unwieldy inter-process communication mechanisms as adopted in traditional multi-tasking systems won't be needed. Example inter-process communication mechanisms may include, semaphores, spinlocks, etc.

Abstract: A transaction is detected. The transaction has a begin-transaction indication and an end-transaction indication. If it is determined that the begin-transaction indication is not a no-speculation indication, then the transaction is processed.

Abstract: Portions of configuration state registers in-memory. An instruction is obtained, and a determination is made that the instruction accesses a configuration state register. A portion of the configuration state register is in-memory and another portion of the configuration state register is in-processor. Processing associated with the configuration state register is performed. The performing processing is based on a type of access and whether the portion or the other portion is being accessed.

Abstract: A processor and methods are provided for detecting fault in a control flow. The processor includes an instruction set architecture defining a pair of FLOWSET and FLOWCHECK opcodes and FLOWSET and FLOWCHECK operations. This pair of opcodes and associated operation works together with a CFI shadow stack to detect faults in an intended flow of instructions. Upon detection of a fault, a fault notice is provided. The methods of detecting fault in a control flow may be implemented using hardware or software and a shadow stack.

Abstract: A mechanism is provided for improving performance when executing unaligned load instructions which load an unaligned block of data from a data store. In a first unaligned load handling mode, a final load operation of a series of load operations performed for the instruction loads a full data word extending beyond the end of the unaligned block of data to be loaded by that instruction. If an initial portion of the unaligned block of data to be loaded by a subsequent unaligned load instruction corresponds to the excess part in the stream buffer for the earlier instruction, then an initial load operation for the subsequent instruction can be suppressed. A mechanism is also described for allowing series of dependent data access operations triggered by a given instruction to be halted partway through when a stall condition arises, and resumed partway through later, by defining overlapping sequences of transactions.

Abstract: A processor includes a cache memory, an issuing unit that issues, with respect to all element data as a processing object of a load instruction, a cache request to the cache memory for each of a plurality of groups which are divided to include element data, a comparing unit that compares addresses of the element data as the processing object of the load instruction, and determines whether element data in a same group are simultaneously accessible, and a control unit that accesses the cache memory according to the cache request registered in a load queue registering one or more cache requests issued from the issuing unit. The control unit processes by one access whole element data determined to be simultaneously accessible by the comparing unit.

Abstract: Techniques are disclosed relating to selecting store instructions for dispatch to a shared pipeline. In some embodiments, the shared pipeline processes instructions for different target clients with different data rate capabilities. Therefore, in some embodiments, the pipeline is configured to generate state information that is based on a determined amount of work in the pipeline that targets at least one slower target. In some embodiments, the state information indicates whether the amount of work is above a threshold for the particular target. In some embodiments, scheduling circuitry is configured to select instructions for dispatch to the pipeline based on the state information. For example, the scheduling circuitry may refrain from selecting instructions with a slower target when the slower target is above its threshold amount of work in the pipeline.

Abstract: Digital signal processors often operate on two operands per instruction, and it is desirable to retrieve both operands in one cycle. Some data caches connect to the processor over two busses and internally uses two or more memory banks to store cache lines. The allocation of cache lines to specific banks is based on the address that the cache line is associated. When two memory accesses map to the same memory bank, fetching the operands incurs extra latency because the accesses are serialized. An improved bank organization for providing conflict-free dual-data cache access—a bus-based data cache system having two data buses and two memory banks—is disclosed. Each memory bank works as a default memory bank for the corresponding data bus. As long as the two values of data being accessed belong to two separate data sets assigned to the two respective data buses, memory bank conflicts are avoided.

Abstract: A system that includes a guest virtual machine is in communication with a hypervisor. The guest virtual machine comprises virtual machine measurement points and a hypervisor control point. The hypervisor control point is configured to collect virtual machine memory metadata from the guest virtual machine and from the hypervisor, and to compare the virtual machine memory metadata to the hypervisor memory metadata. The hypervisor control point is further configured to determine whether the virtual machine memory metadata is the same as the hypervisor memory metadata and to communicate the virtual machine memory metadata to the virtual vault machine in response to determining that the virtual machine memory metadata is the same as the hypervisor memory metadata. The virtual vault machine is in communication with the hypervisor and configured to classify the state of the guest virtual based on the virtual machine memory metadata.

Abstract: Techniques provide for hardware accelerated data movement between main memory and an on-chip data movement system that comprises multiple core processors that operate on the tabular data. The tabular data is moved to or from the scratch pad memories of the core processors. While the data is in-flight, the data may be manipulated by data manipulation operations. The data movement system includes multiple data movement engines, each dedicated to moving and transforming tabular data from main memory data to a subset of the core processors. Each data movement engine is coupled to an internal memory that stores data (e.g. a bit vector) that dictates how data manipulation operations are performed on tabular data moved from a main memory to the memories of a core processor, or to and from other memories. The internal memory of each data movement engine is private to the data movement engine.

Abstract: A method of profiling the performance of a graphics unit when rendering a scene according to a graphics pipeline, includes executing stages of the graphics pipeline using one or more units of rendering circuitry to perform at least one rendering task that defines a portion of the work required to render the scene, the at least one rendering task associated with a set flag; propagating an indication of the flag through stages of the graphics pipeline as the scene is rendered so that work done as part of the at least one rendering task is associated with the set flag; changing the value of a counter associated with a unit of rendering circuitry in response to an occurrence of an event while that unit performs an item of work associated with the set flag; and reading the value of the counter to thereby measure the occurrences of the event caused by completing the at least one rendering task.

Abstract: A system and a method to cascade execution of instructions in a load-store unit (LSU) of a central processing unit (CPU) to reduce latency associated with the instructions. First data stored in a cache is read by the LSU in response a first memory load instruction of two immediately consecutive memory load instructions. Alignment, sign extension and/or endian operations are performed on the first data read from the cache in response to the first memory load instruction, and, in parallel, a memory-load address-forwarded result is selected based on a corrected alignment of the first data read in response to the first memory load instruction to provide a next address for a second of the two immediately consecutive memory load instructions. Second data stored in the cache is read by the LSU in response to the second memory load instruction based on the selected memory-load address-forwarded result.

Abstract: A programmable processor and method for improving the performance of processors by expanding at least two source operands, or a source and a result operand, to a width greater than the width of either the general purpose register or the data path width. The present invention provides operands which are substantially larger than the data path with of the processor by using the contents of a general purpose register to specify a memory address at which a plurality of data path widths of data can be read or written, as well as the size and shape of the operand. In addition, several instructions and apparatus for implementing these instructions are described which obtain performance advantages if the operands are not limited to the width and accessible number of general purpose registers.

Abstract: Embodiments include processing systems that determine, based on an instruction address range indicator stored in a first register, whether a next instruction fetch address corresponds to a location within a first memory region associated with a current privilege state or within a second memory region associated with a different privilege state. When the next instruction fetch address is not within the first memory region, the next instruction is allowed to be fetched only when a transition to the different privilege state is legal. In a further embodiment, when a data access address is generated for an instruction, a determination is made, based on a data address range indicator stored in a second register, whether access to a memory location corresponding to the data access address is allowed. The access is allowed when the current privilege state is a privilege state in which access to the memory location is allowed.

Abstract: Execution control of computer software instructions. A determination is made as to whether a record exists that indicates an outcome of a previous attempt to execute a computer software instruction in a first execution privilege mode. A current attempt to execute the computer software instruction is controlled by causing the current attempt to execute the computer software instruction in a second execution privilege mode if the record exists and if the outcome indicates that the attempt to execute the computer software instruction in the first execution privilege mode failed.