Abstract: A cache coherent distributed shared memory multi-processor computer system is provided with a memory controller which includes a recall unit. The recall unit allows selective forced write-backs of dirty cache lines to the home memory. After a request is posted in the recall unit, a recall (“flush”) command is issued which forces the owner cache to write-back the dirty cache line to be flushed. The memory controller will inform the recall unit as each recall operation is completed. The recall unit operation will be interrupted when all flush requests are completed.

Abstract: The present invention is a system and method for recovering from memory failures in computer systems. The method of the present invention includes the steps of: identifying a predetermined instruction sequence; monitoring for memory access errors in response to the request; logging a memory access error in an error logging register; polling the register for any logged memory access error during execution of the instruction sequence; and raising exceptions, if the memory access error is logged. Within the system of the present invention, memory access errors are stored in an error logging register, machine check abort handles are masked, and memory controllers are under full control of the software so that memory access errors can be intercepted and responded to without necessitating a system reboot or application restart. The present invention is particularly applicable to O/S code which can not otherwise recover from memory errors except by rebooting.

Abstract: A method is provided for cache flushing in a computer system having a processor, a cache, a synchronization primitive detector, and a cache flush engine. The method includes providing a synchronization primitive from the processor into the computer system; detecting the synchronization primitive in the synchronization primitive detector; providing a trigger signal from the synchronization primitive detector in response to detection of the synchronization primitive; providing cache information from the recall unit into the computer system in response to the trigger signal; and flushing the cache in response to the cache information in the computer system.

Abstract: A cache coherent distributed shared memory multi-processor computer system is provided with a memory controller which includes a recall unit. The recall unit allows selective forced write-backs of dirty cache lines to the home memory. After a request is posted in the recall unit, a recall (“flush”) command is issued which forces the owner cache to write-back the dirty cache line to be flushed. The memory controller will inform the recall unit as each recall operation is completed. The recall unit operation will be interrupted when all flush requests are completed.

Abstract: The present invention is a system and method for recovering from memory failures in computer systems. The method of the present invention includes the steps of: identifying a predetermined instruction sequence; monitoring for memory access errors in response to the request; logging a memory access error in an error logging register; polling the register for any logged memory access error during execution of the instruction sequence; and raising exceptions, if the memory access error is logged. Within the system of the present invention, memory access errors are stored in an error logging register, machine check abort handles are masked, and memory controllers are under full control of the software so that memory access errors can be intercepted and responded to without necessitating a system reboot or application restart. The present invention is particularly applicable to O/S code which can not otherwise recover from memory errors except by rebooting.

Abstract: A method and apparatus for data security for a distributed file system. A distributed file system interface is coupled to the one or more client applications, and a storage server and a meta-data server are coupled to the distributed file system interface. The meta-data server receives open-file requests from the distributed file system interface and in response creates a security object. The meta-data server also generates an partial encryption key and stores the partial encryption key in the security object. The block storage server completes the encryption key, and the meta-data server encrypts the list of blocks that are in the file and stores the encrypted block list in the security object. The security object is then returned to the distributed file interface and used in subsequent file access requests.