MULTIPLE-QUEUE MULTIPLE-RESOURCE ENTRY SLEEP AND WAKEUP FOR POWER SAVINGS AND BANDWIDTH CONSERVATION IN A RETRY BASED PIPELINE

• US 20150160720A1
• Filed: 10/21/2014
• Published: 06/11/2015
• Est. Priority Date: 12/26/2009
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Vash, James R., Ahuja, Pritpal S., Jung, Bongjin, Chamberlain, Jeffrey D.
• Granted Patent: US 9,207,753 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/3293 by switching to a less power-consuming processor, e.g. sub-CPU
• CPC Class Codes: G06F 13/00 Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units interface circuits for specific input/output devices G06F3/00 ; multiprogram control therefor G06F9/46; multiprocessor systems G06F15/16
• CPC Class Codes: G06F 13/1642 with request queuing
• CPC Class Codes: H04L 69/00 Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass networks security protocols H04L9/40; wireless communication networks H04W
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Methods and apparatus relating to multiple-queue multiple-resource entry sleep and wakeup for power savings and bandwidth conservation in a retry based pipeline are described. In one embodiment, a bit indicates whether a corresponding queue entry is asleep or awake with respect to arbitration for resources in a retry based pipeline. Furthermore, multiple entries from different queues may be grouped together and multiple resources may be grouped together. Other embodiments are also disclosed.

Claims

1. An apparatus comprising:

a first queue to store a first plurality of entries; and

a second queue to store a second plurality of entries;

wherein each of the first plurality of entries and second plurality of entries is to comprise a first bit to indicate whether an entry is asleep and wherein an arbitration of the entry is to be performed based on a status of the first bit.

2. The apparatus of claim 1, wherein the first bit is to indicate whether the entry is asleep due to unavailability of a resource.

3. The apparatus of claim 1, wherein the first bit is to indicate whether the entry is asleep due to unavailability of a plurality of resources.

4. The apparatus of claim 1, wherein the first bit is modified to indicate the entry is asleep based on unavailability of a resource.

5. The apparatus of claim 4, wherein upon return of the resource, the first bit is to be modified to indicate the entry is awake for arbitration.

6. The apparatus of claim 4, wherein a third plurality of a subset of the first plurality of entries and second plurality of entries are to be grouped into a region and wherein upon return of the resource, the first bit of all entries in the region is to be modified as a group to indicate that all entries in the region are awake for arbitration.

7. The apparatus of claim 1, wherein the first plurality of entries correspond to a plurality of local requests and wherein the second plurality of entries correspond to a plurality of remote requests.

8. The apparatus of claim 1, further comprising a third queue to store a third plurality of entries corresponding to a plurality of cache victims.

9. The apparatus of claim 1, further comprising logic to select a region, corresponding to a set of entries among the first and second queues, to be awakened based on:

region sleep flags or region priorities.

10. The apparatus of claim 1, further comprising logic to divide entries into new and old entries, wherein an old entry has been negatively acknowledged when its queue is in normal mode and wherein remaining entries are considered new.

11. The apparatus of claim 1, wherein the first bit is modified to indicate the entry is asleep based on unavailability of a resource and wherein upon return of the resource, the first bit is to be modified for all entries in a region to indicate the region is awake for arbitration based on a round-robin selection.

12. The apparatus of claim 1, further comprising a retry based pipeline coupled to the first or second queues to service requests of the first or second queues.

13. A method comprising:

storing a first plurality of entries in a first queue;

storing a second plurality of entries in a second queue, wherein each of the first plurality of entries and second plurality of entries is to comprise a first bit to indicate whether an entry is asleep; and

determining whether to arbitrate the entry in a retry based pipeline based on a status of the first bit.

14. The method of claim 13, further comprising modifying the first bit in response to availability of a resource in the retry based pipeline.

15. The method of claim 14, further comprising selecting which entries from the first and second plurality of entries are to be awakened in response to availability of the resource.

16. The method of claim 14, further comprising selecting which region is to be awakened in response to availability of the resource and based on a priority of a plurality of regions.

17. A system comprising:

one or more of a first queue and second queue, wherein the first queue is to store a first plurality of entries and the second queue is to store a second plurality of entries; and

a processor to modify a first bit, corresponding to each of the first plurality of entries and second plurality of entries, to indicate whether an entry is asleep,

wherein an arbitration of the entry is to be performed based on a status of the first bit.

18. The system of claim 17, wherein the processor is to prioritize waking of the first and second plurality of entries.

19. The system of claim 17, wherein the first bit is modified to indicate the entry is asleep based on unavailability of a resource in a bucket and wherein upon return of any resource in the bucket, the first bit is to be modified to indicate the entry is awake for arbitration when a region corresponding to the entry is chosen based on a round-robin selection.

20. The system of claim 17, wherein the first bit is to indicate whether the entry is asleep due to unavailability of a resource.