| 摘要 |
Initially, data is copied from a disk to a page frame and then to a read buffer, for instance. Next, a check is made to determine whether the percent of real memory occupied by file pages is less than a preset maximum volume. If so, no space is allocated for additional file page and no page frames are returned to the free list. If not, the VMM selects the best candidate file pages in real memory and returns them to the free list. Ideal candidates are a thread's memory pages, from a thread doing sequential I/O the file system. In so doing, the page frames are added to the free list as soon as the I/O is complete.
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