Priority based context preemption

• US 9,396,032 B2
• Filed: 03/27/2014
• Issued: 07/19/2016
• Est. Priority Date: 03/27/2014
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Nalluri, Hema C., Navale, Aditya, Doyle, Peter L., Ramadoss, Murali, Vembu, Balaji, Boles, Jeffery S.
• Primary Examiner(s): Lee, Adam
• Application Number:
  US14/227,692
• Publication Number:
  US 20150277981A1
• Time in Patent Office: 845 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
• CPC Class Codes: G06F 9/5038 considering the execution order of a plurality of tasks, e.g. taking priority or time dependency constraints into consideration scheduling strategies G06F9/4881 and subgroups
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining

Abstract

Methods and apparatuses may prioritize the processing of high priority and low priority contexts submitted to a processing unit through separate high priority and low priority context submission ports. According to one embodiment, submission of a context to the low priority port causes contexts in progress to be preempted, whereas submission of a context to the high priority port causes contexts in progress to be paused.

Claims

1. A system comprising:

a processor;

a pipeline;

a first port to receive contexts having a first priority;

a second port to receive contexts having a second priority that is higher than the first priority;

a context detection module to detect receipt of the contexts having the second priority at the second port;

a pre-emption module to pre-empt a context having the first priority in the pipeline, wherein to pre-empt the context having the first priority in the pipeline is to include flushing the pipeline by permitting the context having the first priority already in the pipeline to complete execution when the first port receives another context having the first priority;

a pause module to pause the context having the first priority in the pipeline before it completes in the pipeline and without flushing the pipeline after the context detection module has detected the receipt of a context having the second priority at the second port; and

on-die storage to store a state of the paused context.

2. The system of claim 1, wherein the on-die storage and the processor are on a common die.

3. The system of claim 2, further comprising a restoration module to restore a paused context after the context having the second priority has been completed.

4. The system of claim 3, wherein at least one of the modules is implemented in software.

5. The system of claim 1, wherein the pause module is implemented in hardware.

6. The system of claim 1, further comprising a preemption restoration module to restore a context that has been pre-empted.

7. The system of claim 1, further comprising a pause restoration module to restore a context that has been paused.

8. The system of claim 1, comprising a three-dimensional (3D) graphics processor.

9. A method comprising:

submitting a first context to a first port dedicated to contexts having a first priority;

submitting the first context to a pipeline;

pre-empting the first context in the pipeline by flushing the pipeline so as to permit the first context already in the pipeline to complete execution when another context has been submitted to the first port;

submitting a second context to a second port dedicated to contexts having a second priority, wherein the second priority is higher than the first priority;

in response to submitting the second context to the second port, pausing the first context already in the pipeline before it completes in the pipeline, wherein the pipeline is not flushed; and

saving a state of the paused context.

10. The method of claim 9, further including detecting the submission of the second context to the second port.

11. The method of claim 9, further including copying a state and unfinished work of the first context to on-die storage and then submitting the second context to the pipeline.

12. The method of claim 11, further including resuming the first context after the second context has been completed.

13. At least one non-transitory computer readable storage medium comprising a set of instructions which, if executed by a computing device, cause the computing device to:

submit a first context to a first port dedicated to contexts having a first priority;

submit the first context to a pipeline;

pre-empt the first context in the pipeline by flushing the pipeline so as to permit the first context already in the pipeline to complete execution when another context has been submitted to the first port;

submit a second context to a second port dedicated to contexts having a second priority, wherein the second priority is higher than the first priority;

in response to submitting the second context to the second port, pause the first context already in the pipeline before it completes in the pipeline, wherein the pipeline is not flushed; and

save a state of the paused context.

14. The at least one non-transitory computer readable storage medium of claim 13, wherein the instructions, if executed, cause a computing device to detect the submission of the second context to the second port.

15. The at least one non-transitory computer readable storage medium of claim 13, wherein the instructions, if executed, cause a computing device to copy a state and unfinished work of the first context to on-die storage and then submit the second context to the pipeline.

16. The at least one non-transitory computer readable storage medium of claim 15, wherein the instructions, if executed, cause a computing device to resume the first context after the second context has been completed.

17. An apparatus comprising:

a first port to receive contexts of a first priority;

a second port to receive contexts of a second priority;

a pipeline to process contexts;

a context detection module to detect the submission of contexts to the ports;

a scheduler module to send contexts to the pipeline;

a pre-emption module to pre-empt a context having the first priority in the pipeline, wherein to pre-empt the context having the first priority in the pipeline is to include flushing the pipeline by permitting the context having the first priority already in the pipeline to complete execution when the first port receives another context having the first priority;

a pause module to pause the pipeline processing the context having the first priority before it completes in the pipeline and without flushing the pipeline when a context having the second priority is received at the second port, wherein the second priority is higher than the first priority; and

on-die storage to store a state of at least one of the paused contexts.

18. The apparatus of claim 17, further comprising a restoration module to restore a context to the pipeline.

19. The apparatus of claim 17, further comprising memory to store state information concerning contexts.

20. The apparatus of claim 17, further comprising a graphical processing unit.

21. The apparatus of claim 17, further comprising a paused context restore module to resume a paused context after the completion of a context submitted to the second port.