CSC/ECE 506 Spring 2013/7a bs - Revision history

Bvumman: /* References */

2013-03-25T15:03:38Z

References

← Older revision		Revision as of 15:03, 25 March 2013
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	d) Broadcast Distributed Manager Algorithm doesn’t scale well.		d) Broadcast Distributed Manager Algorithm doesn’t scale well.

	Quiz Answers: '''1. b,c		Quiz Answers: '''1. b,c 2. b 3. c 4. b,c 5. b 6. a,c 7. c 8. a,d'''
	2. b
	3. c
	4. b,c
	5. b
	6. a,c
	7. c
	8. a,d
	'''

Bvumman: /* References */

2013-03-25T15:03:02Z

References

← Older revision		Revision as of 15:03, 25 March 2013
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	d) Broadcast Distributed Manager Algorithm doesn’t scale well.		d) Broadcast Distributed Manager Algorithm doesn’t scale well.

	Quiz Answers: 1. b,c		Quiz Answers: '''1. b,c
	2. b		2. b
	3. c		3. c
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	7. c		7. c
	8. a,d		8. a,d
			'''

Bvumman: /* References */

2013-03-25T15:02:27Z

References

← Older revision		Revision as of 15:02, 25 March 2013
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	d) Broadcast Distributed Manager Algorithm doesn’t scale well.		d) Broadcast Distributed Manager Algorithm doesn’t scale well.

			Quiz Answers: 1. b,c
			2. b
			3. c
			4. b,c
			5. b
			6. a,c
			7. c
			8. a,d

Bvumman: /* References */

2013-03-25T14:47:54Z

References

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	a) No difference		a) No difference

	b) ~~Fork Consistency~~ Model has only one copy of the file.		b) One copy Serializabilty Model has only one copy of the file.

	c) Sequential Consistency Model has only one copy of the file.		c) Sequential Consistency Model has only one copy of the file.

Bvumman: /* References */

2013-03-25T14:47:20Z

References

← Older revision		Revision as of 14:47, 25 March 2013
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	2.What is the major difference between ~~Fork consistency~~ and Sequential consistency?		2.What is the major difference between One copy Serializabilty and Sequential consistency?

	a) No difference		a) No difference

Bvumman at 01:39, 21 March 2013

2013-03-21T01:39:42Z

← Older revision		Revision as of 01:39, 21 March 2013
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	[http://en.wikipedia.org/wiki/Cache_coherency '''Cache coherence'''] refers to the consistency of data stored in local caches of a shared resource.		[http://en.wikipedia.org/wiki/Cache_coherency '''Cache coherence'''] refers to the consistency of data stored in local caches of a shared resource.

	[[Image:Cache_Coherency_Generic.png\|center\|Cache Coherence]]		[[Image:Cache_Coherency_Generic.png\|400px\|center\|Cache Coherence]]

Bvumman: /* Update Coherence Protocols */

2013-03-21T01:36:57Z

Update Coherence Protocols

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	*'''Firefly protocol'''		*'''Firefly protocol'''
	This is another example of update-based coherence cache protocols.Unlike the Dragon Protocol, the caches use a [http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies write-through policy] and hence writes all changes to memory.This protocol uses a special bus technique called SharedLine to allow quick detection to copies of the block in other caches. It is similar to the COPIES_EXIST (C) and !COPIES_EXIST. In the firefly protocol , there is no invalidation state just like the dragon protocol as the cache blocks are never invalidated.		This is another example of update-based coherence cache protocols.Unlike the Dragon Protocol, the caches use a [http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies write-through policy] and hence writes all changes to memory.This protocol uses a special bus technique called SharedLine to allow quick detection to copies of the block in other caches. It is similar to the COPIES_EXIST(C) and !COPIES_EXIST. In the firefly protocol , there is no invalidation state just like the dragon protocol as the cache blocks are never invalidated.

	====Hybrid Protocols<ref>http://wiki.expertiza.ncsu.edu/index.php/User:Stchen#Introduction_to_Update_and_Adaptive_Coherence_Protocols_on_Real_Architectures</ref>====		====Hybrid Protocols<ref>http://wiki.expertiza.ncsu.edu/index.php/User:Stchen#Introduction_to_Update_and_Adaptive_Coherence_Protocols_on_Real_Architectures</ref>====

Bvumman: /* Update Coherence Protocols */

2013-03-21T01:36:37Z

Update Coherence Protocols

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	The [http://en.wikipedia.org/wiki/Dragon_protocol Dragon Protocol] is an update-based coherence protocol. It reduces [http://en.wikipedia.org/wiki/Bandwidth_(computing) bandwidth] as it updates the specific words instead of entire block within the cache.[http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies Write allocate] and write update policies are used by the caches. The Dragon Protocol consists of four states (Modified (M), Exclusive (E), Shared Clean (Sc), and Shared Modified (Sm)) and there is no invalidation state,because every block present in the cache is valid.		The [http://en.wikipedia.org/wiki/Dragon_protocol Dragon Protocol] is an update-based coherence protocol. It reduces [http://en.wikipedia.org/wiki/Bandwidth_(computing) bandwidth] as it updates the specific words instead of entire block within the cache.[http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies Write allocate] and write update policies are used by the caches. The Dragon Protocol consists of four states (Modified (M), Exclusive (E), Shared Clean (Sc), and Shared Modified (Sm)) and there is no invalidation state,because every block present in the cache is valid.

	[[File:Dragon.jpg\|thumb\|center\|Dragon State Diagram\|~~600px~~]]		[[File:Dragon.jpg\|thumb\|center\|Dragon State Diagram\|700px]]

	*'''Firefly protocol'''		*'''Firefly protocol'''

Bvumman: /* Update Coherence Protocols */

2013-03-21T01:36:26Z

Update Coherence Protocols

← Older revision		Revision as of 01:36, 21 March 2013
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	The [http://en.wikipedia.org/wiki/Dragon_protocol Dragon Protocol] is an update-based coherence protocol. It reduces [http://en.wikipedia.org/wiki/Bandwidth_(computing) bandwidth] as it updates the specific words instead of entire block within the cache.[http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies Write allocate] and write update policies are used by the caches. The Dragon Protocol consists of four states (Modified (M), Exclusive (E), Shared Clean (Sc), and Shared Modified (Sm)) and there is no invalidation state,because every block present in the cache is valid.		The [http://en.wikipedia.org/wiki/Dragon_protocol Dragon Protocol] is an update-based coherence protocol. It reduces [http://en.wikipedia.org/wiki/Bandwidth_(computing) bandwidth] as it updates the specific words instead of entire block within the cache.[http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies Write allocate] and write update policies are used by the caches. The Dragon Protocol consists of four states (Modified (M), Exclusive (E), Shared Clean (Sc), and Shared Modified (Sm)) and there is no invalidation state,because every block present in the cache is valid.

	[[File:Dragon.jpg\|thumb\|center\|Dragon State Diagram\|~~500px~~]]		[[File:Dragon.jpg\|thumb\|center\|Dragon State Diagram\|600px]]

	*'''Firefly protocol'''		*'''Firefly protocol'''

Bvumman: /* Update Coherence Protocols */

2013-03-21T01:36:13Z

Update Coherence Protocols

← Older revision		Revision as of 01:36, 21 March 2013
Line 93:		Line 93:
	The [http://en.wikipedia.org/wiki/Dragon_protocol Dragon Protocol] is an update-based coherence protocol. It reduces [http://en.wikipedia.org/wiki/Bandwidth_(computing) bandwidth] as it updates the specific words instead of entire block within the cache.[http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies Write allocate] and write update policies are used by the caches. The Dragon Protocol consists of four states (Modified (M), Exclusive (E), Shared Clean (Sc), and Shared Modified (Sm)) and there is no invalidation state,because every block present in the cache is valid.		The [http://en.wikipedia.org/wiki/Dragon_protocol Dragon Protocol] is an update-based coherence protocol. It reduces [http://en.wikipedia.org/wiki/Bandwidth_(computing) bandwidth] as it updates the specific words instead of entire block within the cache.[http://en.wikipedia.org/wiki/Cache_(computing)#Writing_policies Write allocate] and write update policies are used by the caches. The Dragon Protocol consists of four states (Modified (M), Exclusive (E), Shared Clean (Sc), and Shared Modified (Sm)) and there is no invalidation state,because every block present in the cache is valid.

	[[File:Dragon.jpg\|thumb\|center\|Dragon State Diagram\|~~700px~~]]		[[File:Dragon.jpg\|thumb\|center\|Dragon State Diagram\|500px]]

	*'''Firefly protocol'''		*'''Firefly protocol'''