Page Bits

Page Bits - by MMU – Permission: Page Bits • If a CPU...

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Page Bits Each entry in the page table needs only 20 bits to store the page number. The remaining 12 bits are used to store characteristics of the page. Resident Bit: Page is resident in RAM instead of swap space/file. Modified Bit: Page has been modified since the last time the bit was cleared. Set by the MMU. Access Bit: Page has been read since the last time the bit was cleared. Set
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Unformatted text preview: by MMU – Permission: Page Bits • If a CPU operation exceeds the permissions of a page, the MMU will generate an interrupt (page fault). The interrupt may be translated into a signal (SEGV, SIGBUS) to the process. • If a page is accessed and the page is not resident in RAM, the MMU generates an interrupt to the kernel and the kernel loads that page from disk....
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This note was uploaded on 01/30/2012 for the course CS 354 taught by Professor Staff during the Fall '08 term at Purdue.

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Page Bits - by MMU – Permission: Page Bits • If a CPU...

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