Recovery from data fetch errors in hypervisor code

A logically partitioned data processing system;

• comprising:
• a plurality of processors, each of which assigned to one of a plurality of partitions;
• and
• a plurality of private data areas, each of which is assigned to one of the plurality of processors and each of the plurality of private data areas includes a primary copy of data and an alternate copy of data;
• wherein
• each of the plurality of processors is configured, during data fetch operations, to attempt to retrieve data from the primary copy of the data and, responsive to a failure to retrieve the data from the primary copy, attempting to retrieve the data from the alternate copy of the data;
• and
• each of the plurality of processors is configured, responsive to a failure of a write operation to the primary copy of data, to copy data from the alternate copy of the data into the primary copy of the data and re-attempt the write operation.

A method of preventing a data fetch error occurring within one partition from effecting the operation of other partitions within a logically partitioned data processing system, the method comprising:

• receiving, at a processor, a data fetch error;
• creating an error log file indicating the receipt of the data fetch error;
• and
• initiating a reboot policy for the one partition to which the processor receiving the data fetch error is allocated.

A computer program product in a computer readable media for use in a logically partitioned data processing system for preventing a data fetch error occurring within one partition from effecting the operation of other partitions within the logically partitioned data processing system, the computer program product comprising:

• first instructions for receiving, at a processor, a data fetch error;
• second instructions for creating an error log file indicating the receipt of the data fetch error;
• and
• third instructions for initiating a reboot policy for the one partition to which the processor receiving the data fetch error is allocated.

A system for preventing a data fetch error occurring within one partition from effecting the operation of other partitions within a logically partitioned data processing system, the system comprising:

• first means for receiving, at a processor, a data fetch error;
• second means for creating an error log file indicating the receipt of the data fetch error;
• and
• third means for initiating a reboot policy for the one partition to which the processor receiving the data fetch error is allocated.

A method for preventing data fetch errors occurring within a processor attempting to fetch data from a global data structure from affecting the correct operation of hardware and software within partitions not associated with the processor in a logically partitioned data processing system, the method comprising:

• attempting to obtain a lock on a global data structure;
• responsive to a determination that the lock is not obtained within a time out period, searching a list of failed processors;
• responsive to a determination that the processor holding the lock on the global data structure is contained within the list, executing a lock recovery routine;
• responsive to a determination that the lock recovery routine has mended the global data structure, obtaining the lock and continuing with a requested operation.

A computer program product in a computer readable media for use in a logically partitioned data processing system for preventing data fetch errors occurring within a processor attempting to fetch data from a global data structure from affecting the correct operation of hardware and software within partitions not associated with the processor in the logically partitioned data processing system, the computer program product comprising:

• first instructions for attempting to obtain a lock on a global data structure;
• second instructions, responsive to a determination that the lock is not obtained within a time out period, for searching a list of failed processors;
• third instructions, responsive to a determination that the processor holding the lock on the global data structure is contained within the list, for executing a lock recovery routine;
• fourth instructions, responsive to a determination that the lock recovery routine has mended the global data structure, for obtaining the lock and continuing with a requested operation.

A system for preventing data fetch errors occurring within a processor attempting to fetch data from a global data structure from affecting the correct operation of hardware and software within partitions not associated with the processor in a logically partitioned data processing system, the system comprising:

• first means for attempting to obtain a lock on a global data structure;
• second means, responsive to a determination that the lock is not obtained within a time out period, for searching a list of failed processors;
• third means, responsive to a determination that the processor holding the lock on the global data structure is contained within the list, for executing a lock recovery routine;
• fourth means, responsive to a determination that the lock recovery routine has mended the global data structure, for obtaining the lock and continuing with a requested operation.