Method and computer program product for paging control using a reference structure including a reference bitmap

A computer program product for use in a computer system comprising:

• a recording medium;
• means, recorded on the recording medium, for scanning the reference structure to identify a next selected entry for an IO range building routine;
• means, recorded on the recording medium, for comparing the next selected entry with a set hardlimit value;
• means, recorded on the recording medium, responsive to the next selected entry being greater than the hardlimit value, for exiting the IO range building routine;
• means, recorded on the recording medium, for identifying a shortlimit value;
• means, recorded on the recording medium, for comparing the next selected entry with the identified shortlimit value;
• means, recorded on the recording medium, responsive to the next selected entry being greater than the identified shortlimit value, for exiting the IO range building routine;
• and
• means, recorded on the recording medium, for using a first array for storing entry IDs for selected entries found from scanning the reference structure including means, recorded on the recording medium, for storing a last probed index addressing an array slot containing an entry ID for a most recently retrieved selected entry from the reference structure.

A computer program product for paging control using a reference structure, said computer program product including a plurality of computer executable instructions stored on a computer readable medium, wherein said instructions, when executed by said computer, cause the computer to perform the steps of:

• scanning the reference structure to identify a next selected entry for an IO range building routine;
• comparing the next selected entry with a set hardlimit value;
• responsive to the next selected entry being greater than the hardlimit value, exiting the IO range building routine;
• identifying a shortlimit value;
• comparing the next selected entry with the identified shortlimit value;
• responsive to the next selected entry being greater than the identified shortlimit value, exiting the IO range building routine;
• and
• using a first array for storing entry IDs for selected entries found from scanning the reference structure including the step of storing a last probed index addressing an array slot containing an entry ID for a most recently retrieved selected entry from the reference structure.

A computer system having apparatus for paging control using a reference structure comprising:

• a processor,
• a mainstore coupled to the processor for storing data processed by the processor;
• an auxiliary memory for storing data transferred to and from the mainstore;
• means for scanning the reference structure to identify a next selected entry for an IO range building routine;
• means for comparing the next selected entry with a set hardlimit value;
• means responsive to the next selected entry being greater than the hardlimit value, for exiting the IO range building routine;
• means for identifying a shortlimit value;
• means for comparing the next selected entry with the identified shortlimit value;
• means responsive to the next selected entry being greater than the identified shortlimit value, for exiting the IO range building routine;
• and
• means for using a first array for storing entry IDs for selected entries found from scanning the reference structure including means for storing a last probed index addressing an array slot containing an entry ID for a most recently retrieved selected entry from the reference structure.