发明名称 |
Extended cache state with prefetched stream ID information |
摘要 |
A method of operating a computer system is disclosed in which an instruction having an explicit prefetch request is issued directly from an instruction sequence unit to a prefetch unit of a processing unit. In a preferred embodiment, two prefetch units are used, the first prefetch unit being hardware independent and dynamically monitoring one or more active streams associated with operations carried out by a core of the processing unit, and the second prefetch unit being aware of the lower level storage subsystem and sending with the prefetch request an indication that a prefetch value is to be loaded into a lower level cache of the processing unit. The invention may advantageously associate each prefetch request with a stream ID of an associated processor stream, or a processor ID of the requesting processing unit (the latter feature is particularly useful for caches which are shared by a processing unit cluster). If another prefetch value is requested from the memory hierarchy, and it is determined that a prefetch limit of cache usage has been met by the cache, then a cache line in the cache containing one of the earlier prefetch values is allocated for receiving the other prefetch value.
|
申请公布号 |
US6360299(B1) |
申请公布日期 |
2002.03.19 |
申请号 |
US19990345644 |
申请日期 |
1999.06.30 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
ARIMILLI RAVI KUMAR;ARIMILLI LAKSHMINARAYANA BABA;CLARK LEO JAMES;DODSON JOHN STEVEN;GUTHRIE GUY LYNN;FIELDS, JR. JAMES STEPHEN |
分类号 |
G06F12/08;G06F12/12;(IPC1-7):G06F12/00;G06F13/00 |
主分类号 |
G06F12/08 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|