Electrical computers and digital processing systems: memory – Address formation – Address mapping
Patent
1997-11-26
2000-02-15
Thai, Tuan V.
Electrical computers and digital processing systems: memory
Address formation
Address mapping
711200, 711203, 711 3, G06F 1200
Patent
active
060264756
ABSTRACT:
A method and apparatus for dynamically updating virtual to physical address mappings in order to reduce cache thrashing is disclosed in an example computer system having a memory apportioned into a number of pages. A cache is included in the computer system to store a subset of the pages of memory. Each of the pages of memory is addressed by a physical address that includes a cache page address portion. The pages of cache memory are accessed using a cache page address, which corresponds to the cache page address portion of the physical address of a corresponding page of memory. The disclosed system monitors the activity of virtual addresses and uses the activity of virtual addresses to increment cache page address activity counters. The cache page address activity counters are monitored to identify those cache page addresses that are frequently being accessed within a process to identify potential performance problems, such as thrashing. When a cache page address activity count has exceeded a pre-determined threshold, a virtual address associated with that cache page address is mapped to a different physical address having a different cache page address. The new cache page address that is selected for remapping purposes is selected to maintain an even distribution of cache page addresses on a system and process level. The physical page formerly mapped to the virtual address that was associated with a highly active cache page address is returned to a free list of the system, for use by another process. With such an arrangement, adjustments may be made to the virtual to physical translations during execution of a given process in order to improve the overall performance of the process and the overall system.
REFERENCES:
patent: 4563737 (1986-01-01), Nakamura et al.
patent: 5297265 (1994-03-01), Frank et al.
patent: 5428758 (1995-06-01), Salsburg
patent: 5522045 (1996-05-01), Sandberg
patent: 5592625 (1997-01-01), Sandberg
patent: 5699539 (1997-12-01), Garber et al.
patent: 5881302 (1999-03-01), Omata
patent: 5890201 (1999-03-01), McLellan et al.
Digital Equipment Corporation
Thai Tuan V.
LandOfFree
Method for dynamically remapping a virtual address to a physical does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for dynamically remapping a virtual address to a physical, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for dynamically remapping a virtual address to a physical will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1915295