Patent ID: 7627621

Claim:
A method for minor garbage collection comprising: marking a plurality of cards as clean, wherein the plurality of cards designates ranges of memory locations in a shared older generation; marking a card selected from the plurality of cards as dirty to obtain a dirty card when a reference field of an object is modified, wherein the object is allocated in a promotion area selected from a plurality of promotion areas, wherein the promotion area is used to promote objects to the shared older generation only for a single task, and wherein a memory location of the reference field is designated by the card; examining the plurality of promotion areas and the plurality of cards to identify a region of the dirty card overlapping the promotion area, wherein promotion areas associated with other tasks are ignored; scanning the region of the dirty card overlapping the promotion area to identify roots of live young objects associated with the single task; and freeing a young object associated with the single task not identified as live during scanning.