Non-snoop read/write operations in a system supporting snooping
Techniques that may utilize generic tracker structures to provide data coherency in a multi-node system that supports non-snoop read and write operations. The trackers may be organized as a two-dimensional queue structure that may be utilized to resolve conflicting read and/or write operations. Multiple queues having differing associated priorities may be utilized.
1. An apparatus comprising:
a plurality of point-to-point interfaces to communicate with remote processing entities;
a plurality of trackers configured to function as a plurality of queues to store non-snoop read and/or non-snoop write operations in order of reception and categorized by associated priority, the trackers to provide data coherency in a multi-node system including the remote processing entities, wherein the trackers are organized as a two-dimensional queue structure to resolve conflicts between conflicting read and write operations, the trackers to be utilized in processing both non-snoop and snoop operations; and
a control circuit coupled with the plurality of trackers to cause the highest priority, non-conflicted non-snoop read/non-conflicted non-snoop write operation to be performed.
2. The apparatus of claim 1 wherein at least one of the remote processing entities comprises a processing core.
3. The apparatus of claim 1 wherein at least one of the remote processing entities comprises a memory controller.
4. The apparatus of claim 1 wherein one or more of the trackers comprise a register.
5. The apparatus of claim 1 wherein the plurality of queues comprise:
a critical first in, first out (FIFO) queue;
a priority FIFO queue;
an ordered FIFO queue; and
an unordered queue.
6. A system comprising:
a dynamic random access memory (DRAM)
a plurality of point-to-point interfaces to communicate with remote processing entities;
a plurality of trackers configured to function as a plurality of queues to store non-snoop read and/or non-snoop write operations in order of reception and categorized by associated priority, the trackers to provide data coherency in a multi-node system including the remote processing entities, wherein the trackers are organized as a two-dimensional queue structure to resolve conflicts between conflicting read and write operations, the trackers to be utilized in processing both non-snoop and snoop operations; and
a control circuit coupled with the plurality of trackers to cause the highest priority, non-conflicted non-snoop read/non-conflicted non-snoop write operation to be performed utilizing the DRAM.
7. The system of claim 6 wherein at least one of the remote processing entities comprises a processing core.
8. The system of claim 6 wherein at least one of the remote processing entities comprises a memory controller.
9. The system of claim 6 wherein one or more of the trackers comprise a register.
10. The system of claim 6 wherein the plurality of queues comprise:
a critical first in, first out (FIFO) queue;
a priority FIFO queue;
an ordered FIFO queue; and
an unordered queue.
11. A method comprising:
maintaining a plurality of tracking structures organized as at least two or more queues to store posted non-snoop memory access operations, the two or more queues having associated priorities, the trackers to provide data coherency in a multi-node system, wherein the trackers are organized as a two-dimensional queue structure to resolve conflicts between conflicting read and write operations, the trackers to be utilized in processing both non-snoop and snoop operations;
receiving a non-snoop memory access operation;
determining whether a posted non-snoop memory access operation conflicts with the received non-snoop memory access operation; and
halting processing of at least one higher priority queue in favor of a lower priority queue to resolve the conflict between the posted non-snoop memory access operation and the received non-snoop memory access operation.
12. The method of claim 11 , wherein the two or more queues comprise:
a critical first in, first out (FIFO) queue;
a priority FIFO queue;
an ordered FIFO queue; and
an unordered queue.
13. The method of claim 11 wherein the two or more queues comprise one or more general-purpose trackers.
14. The method of claim 13 wherein one or more of the trackers comprise a register.
15. The method of claim 13 wherein one or more of the trackers comprise a memory location.
16. An article comprising a computer-readable medium having stored thereon instructions that, when executed, cause one or more processors to:
maintain a plurality of tracking structures organized as at least two or more queues to store posted non-snoop memory access operations, the two or more queues having associated priorities, the trackers to provide data coherency in a multi-node system, wherein the trackers are organized as a two-dimensional queue structure to resolve conflicts between conflicting read and write operations, the trackers to be utilized in processing both non-snoop and snoop operations;
receive a non-snoop memory access operation;
determine whether a posted non-snoop memory access operation conflicts with the received non-snoop memory access operation; and
halt processing of at least one higher priority queue in favor of a lower priority queue to resolve the conflict between the posted non-snoop memory access operation and the received non-snoop memory access operation.
17. The article of claim 16 , wherein the two or more queues comprise:
a critical first in, first out (FIFO) queue;
a priority FIFO queue;
an ordered FIFO queue; and
an unordered queue.
18. The article of claim 17 wherein the two or more queues comprise one or more general-purpose trackers.
19. The article of claim 18 wherein one or more of the trackers comprise a register.