|
|
|
|
|
| The
Berkeley |
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| protocol is |
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| representative
of |
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| how
typical bus- |
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| based
SMPs work |
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|
|
|
|
| Q: What has to |
|||
| happen
on a |
|||
| “Bus
read |
|||
| miss”? |
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|
|
|
|
| 1. INVALID |
|||
| 2. VALID:
clean, potentially shared, unowned |
|||
| 3.
SHARED-DIRTY: modified, possibly shared, owned |
|||
| 4. DIRTY: modified,
only copy, owned |
|||
| Advanced Computer Architecture Chapter 7.25 |