Abstract: Methods and apparatus are provided for: monitoring processor tasks and associated processor loads therefor that are allocated to be performed by respective sub-processing units associated with a main processing unit; detecting whether a processing error has occurred in a given one of the sub-processing units; re-allocating all of the processor tasks of the given sub-processing unit to one or more participating sub-processing units, including other sub-processing units associated with the main processing unit, based on the processor loads of the processor tasks of the given sub-processing unit and the processor loads of the participating sub-processing units; and at least one of: (i) shutting down, and (ii) re-booting the given sub-processing unit.

Abstract: Methods and apparatus are provided for: monitoring processor tasks and associated processor loads therefor that are allocated to be performed by respective sub-processing units associated with a main processing unit; detecting whether a processing error has occurred in a given one of the sub-processing units; re-allocating all of the processor tasks of the given sub-processing unit to one or more participating sub-processing units, including other sub-processing units associated with the main processing unit, based on the processor loads of the processor tasks of the given sub-processing unit and the processor loads of the participating sub-processing units; and at least one of: (i) shutting down, and (ii) re-booting the given sub-processing unit.

Abstract: Methods and apparatus are provided for disabling error handling countermeasures in various processing contexts, such as by monitoring whether a given processing context requires error handling countermeasures; and disabling any recoverable error correction countermeasures when such countermeasures are not required.

Abstract: Methods and apparatus are provided for: monitoring processor tasks and associated processor loads therefor that are allocated to be performed by respective sub-processing units associated with a main processing unit; detecting whether a processing error has occurred in a given one of the sub-processing units; re-allocating all of the processor tasks of the given sub-processing unit to one or more participating sub-processing units, including other sub-processing units associated with the main processing unit, based on the processor loads of the processor tasks of the given sub-processing unit and the processor loads of the participating sub-processing units; and at least one of: (i) shutting down, and (ii) re-booting the given sub-processing unit.

Abstract: A cache write back operation, write back modified data to memory from cache data array to fix inconsistency between them can be cancelled by the results of a comparison of the progress between a write back and snoop push or snoop kill operation. Write back is intended to make an empty slot to accommodate a reload data due to a cache miss and since a snoop push or snoop kill operation creates an invalid entry in the cache, write back is not needed. If simultaneous push or kill with write back operation exist, then write back machine is late cancelled. System performance improves due to preserving more cache lines in cache data array for possible future reuse.

Abstract: In the structure of register files composed of a master register file and a working register file, when data is read, the working register file is accessed. When data is written, the both the master register file and the working register file are accessed. In the working register file, data of the current window, and data preceded thereby, and data followed thereby are stored. Thus, even if the SAVE instruction or the RESTORE instruction are successively executed, instructions can be processed out of order. As a result, the efficiency of the process is improved.

Abstract: A method and an apparatus are provided for enhancing lock acquisition in a multiprocessor system. A lock-load instruction is sent from a first processor to a cache. In response, a reservation flag for the first processor is set, and lock data is sent to the first processor. The lock data is placed in target and shadow registers of the first processor. Upon a determination that the lock is taken, the lock-load instruction is resent from the first processor to the cache. Upon a determination that the reservation flag is still set for the first processor, a status-quo signal is sent to the first processor without resending the lock data to the first processor. In response, the lock data is copied from the shadow register to the target register.

Abstract: Methods and apparatus are provided for disabling error handling countermeasures in various processing contexts, such as by monitoring whether a given processing context requires error handling countermeasures; and disabling any recoverable error correction countermeasures when such countermeasures are not required.

Abstract: The present invention provides parallel processing of write-back and reload operations in a cache system and optimum circuit utilisation by implementing moveable buffers in a cache storage. However, the data and associated pointers are not permanently assigned to a particular buffer—hence, the buffers can move logically around in the facility. Reload pointer is pointing to an empty entry so that retrieved data from the main memory or equal hierarchy cache on cache miss can be always be accommodated. Victim pointer is always pointing to a modified entry for the next candidate of write-back operation. Write-back operation is necessary with reload operation in order to make a free entry for further cache miss handling unless free entry exists. Because of these moveable pointers for reload buffer and victim buffer and integrated write-back buffer in the cache, intra cache data movement is not necessary which improves cache miss handling performance.

Abstract: The present invention provides for managing an atomic facility cache write back state machine. A first write back selection is made. A reservation pointer pointing to the reserved line in the atomic facility data array is established. A next write back selection is made. An entry for the reservation point for the next write back selection is removed, whereby the valid reservation line is precluded form being selected for the write back. This prevents a modified command from being invalidated.

Abstract: A cache write back operation, write back modified data to memory from cache data array to fix inconsistency between them can be cancelled by the results of a comparison of the progress between a write back and snoop push or snoop kill operation. Write back is intended to make an empty slot to accommodate a reload data due to a cache miss and since a snoop push or snoop kill operation creates an invalid entry in the cache, write back is not needed. If simultaneous push or kill with write back operation exist, then write back machine is late cancelled. System performance improves due to preserving more cache lines in cache data array for possible future reuse.

Abstract: Methods and apparatus are provided for: monitoring processor tasks and associated processor loads therefor that are allocated to be performed by respective sub-processing units associated with a main processing unit; detecting whether a processing error has occurred in a given one of the sub-processing units; re-allocating all of the processor tasks of the given sub-processing unit to one or more participating sub-processing units, including other sub-processing units associated with the main processing unit, based on the processor loads of the processor tasks of the given sub-processing unit and the processor loads of the participating sub-processing units; and at least one of: (i) shutting down, and (ii) re-booting the given sub-processing unit.

Abstract: A method and an apparatus are provided for enhancing lock acquisition in a multiprocessor system. A lock-load instruction is sent from a first processor to a cache. In response, a reservation flag for the first processor is set, and lock data is sent to the first processor. The lock data is placed in target and shadow registers of the first processor. Upon a determination that the lock is taken, the lock-load instruction is resent from the first processor to the cache. Upon a determination that the reservation flag is still set for the first processor, a status-quo signal is sent to the first processor without resending the lock data to the first processor. In response, the lock data is copied from the shadow register to the target register.

Abstract: In the structure of register files composed of a master register file and a working register file, when data is read, the working register file is accessed. When data is written, the both the master register file and the working register file are accessed. In the working register file, data of the current window, and data preceded thereby, and data followed thereby are stored. Thus, even if the SAVE instruction or the RESTORE instruction are successively executed, instructions can be processed out of order. As a result, the efficiency of the process is improved.

Abstract: A floating-point remainder computing unit computes a remainder R, by obtaining an integer quotient by rounding a floating-point variable C which is obtained from A÷B and judging whether the remainder R can be obtained accurately, separately processing mantissa and exponent parts of floating-point variables B and C and separately obtaining the mantissa part Rf and the exponent part Re of the remainder R if the remainder R can be obtained accurately, and carrying out a floating-point add-subtract process which obtains the remainder R from A−B if C=+1 and A+B if C=−1 if the remainder R cannot be obtained accurately.