发明授权
- 专利标题： Automatic adjustment of the quantity of prefetch data in a disk cache operation
- 专利标题（中）： 在磁盘缓存操作中自动调整预取数据量
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申请号： US270750申请日： 1981-06-05
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公开(公告)号： US4489378A公开(公告)日： 1984-12-18
- 发明人: Jerry D. Dixon , Gerald A. Marazas , Andrew B. McNeill , Gerald U. Merckel
- 申请人： Jerry D. Dixon , Gerald A. Marazas , Andrew B. McNeill , Gerald U. Merckel
- 申请人地址： NY Armonk
- 专利权人： International Business Machines Corporation
- 当前专利权人： International Business Machines Corporation
- 当前专利权人地址： NY Armonk
- 主分类号： G06F12/08
- IPC分类号： G06F12/08 ; G06F13/12 ; G06F9/06 ; G06F13/00
摘要：
When transferring data to a cache memory from an attachment data storage device, additional unrequested information can be transferred at the same time if it is likely that this additional data will soon be requested. The average quantity of data transferred to the cache memory in each operation can be automatically and continually varied in order to maximize the performance advantage provided by the cache memory. When a record of data is requested by the host processor, data is transferred to the cache memory from an attachment data storage device in increments of fixed-length data blocks each containing a sequence of data records, with the number of transferred blocks being determined by the position of a requested data record in its respective data block, and the average number of blocks transferred in any one operation being varied by adjusting threshold position values at which second or third data blocks are transferred.