System and method thereof to optimize boot time of computers having multiple CPU's

• US 9,639,374 B2
• Filed: 06/09/2015
• Issued: 05/02/2017
• Est. Priority Date: 05/09/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Divakaran, Nair Sanil Kumar, Shahi, Aman, Das, Shayori
• Primary Examiner(s): AN, MENG AI T
• Assistant Examiner(s): Chu Joy-Davila, Jorge A
• Application Number:
  US14/734,660
• Publication Number:
  US 20150339129A1
• Time in Patent Office: 693 Days
• CPC Class Codes: G06F 9/4405 Initialisation of multiprocessor systems
• CPC Class Codes: G06F 9/48 Program initiating; Program switching, e.g. by interrupt
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues

Abstract

A method and system is provided for optimizing a boot time of a computer system with at least one CPU, in response to a boot command. The system includes memory and a processor. The processor executes instructions stored in the memory to access a task description chart (TDC) comprising essential tasks related to the booting of the system. The TDC is processed offline to create two sets of scheduling charts: an independent task chart (ITC) and a dependent task chart (DTC). The ITC includes all the independent tasks and the DTC includes all the dependent tasks. The DTC is further divided into DTC1 and DTC2. The tasks from all the charts are selected for execution based on priority. The method and system solve the scheduling overhead problem during the boot process, by optimizing the scheduling.

Claims

1. A computer implemented method, in response to a boot command, for booting a computer system connected to multiple initialized Central Processing Units (CPUs), the computer implemented method comprising:

accessing a task description chart (TDC) stored in the computer system, wherein the TDC includes a plurality of tasks of a booting process, wherein each task of the plurality of booting process includes selection information of the plurality of tasks of the booting process, comprising a priority field, at least one dependency field, a lock field, and a status field;

categorizing, based on the selection information for the plurality of tasks of the booting process, the accessed TDC to generate;

an independent task chart (ITC) comprising a set of independent tasks independent of any other tasks, and

a dependent task chart (DTC) comprising a set of dependent tasks having at least one dependency on another task, wherein the DTC is further categorized into;

a dependent task chart 1 (DTC 1) comprising a first set of dependent tasks from the DTC having at least one dependency on at least one task selected from the set of independent tasks of the ITC, and

a dependent task chart 2 (DTC 2) comprising a second set of dependent tasks from the DTC having at least one dependency on the at least one DTC1 task selected from the first set of dependent tasks of the DTC 1 or at least one task selected from the second set of dependent tasks of the DTC 2;

executing the set of tasks from the ITC by selecting at least one ITC task from the ITC based on the selection information, executing the at least one ITC task, updating a status bit register for completion of the at least one ITC task, and checking for at least one unexecuted task from the ITC, thereby

when all tasks in the set of independent tasks of the ITC are completed, selecting at least one DTC 1 task from the DTC 1 based on the selection information, executing the at least one DTC1 task, updating the status bit register for completion of the at least one DTC 1 task, and checking for at least one unexecuted task from the DTC 1, and thereby

when all tasks in the first set of dependent tasks of the DTC 1 are completed, selecting at least one DTC 2 task from the DTC 2 based on the selection information, executing the at least one DTC 2 task based on the at least one dependency on at least one task selected from the first set of dependent tasks of the DTC 1 or at least one task selected from the second set of dependent tasks of the DTC 2, updating the status bit register for completion of the at least one DTC 2 task, and checking for at least one unexecuted task from the DTC 2.

2. The computer implemented method as claimed in claim 1, wherein the selection information comprises the priority field representing a priority of the plurality of tasks, and the at least one task is selected based on the selection information arranged in an ascending order of the priority by the multiple CPUs.

3. The computer implemented method as claimed in claim 1, wherein the selection information comprises at least one of the dependency field, the lock field, or the status field.

4. The computer implemented method as claimed in claim 1, wherein the TDC is categorized based on the dependency of the plurality of tasks.

5. The computer implemented method as claimed in claim 1, wherein the ITC is arranged and executed in an ascending order of the priority of the set of independent tasks.

6. The computer implemented method as claimed in claim 1, wherein the DTC is arranged in an ascending order of the priority of the set of dependent tasks and the at least one dependency on the other task.

7. The computer implemented method as claimed in claim 6, wherein the other task is at least one task selected from the set of independent tasks of the ITC, or from the first set of dependent tasks of the DTC 1, or from the second set of dependent tasks of the DTC 2.

8. The computer implemented method as claimed in claim 1, wherein the set of independent tasks from the ITC are executed first, the first set of dependent tasks from the DTC 1 are executed after the execution of the set of independent tasks from the ITC, and the second set of dependent tasks from the DTC 2 are executed after the execution of the first set of dependent tasks from the DTC1.

9. The computer implemented method as claimed in claim 1, wherein the second set of tasks from the DTC 2 are executed based on the dependencies of the set of tasks.

10. The computer implemented method as claimed in claim 1, further comprising:

maintaining the status bit register for completion of each task and to check the at least one unexecuted task, wherein the status bit register is stored in a memory.

11. A computer system, comprising:

multiple Central Processing Units (CPUs);

a memory coupled to the multiple CPUs for executing a plurality of instructions stored in the memory, the execution of the instructions causing the multiple CPUs to;

access a task description chart (TDC) stored in the computer system, wherein the TDC includes a plurality of tasks of a booting process, wherein each task of the plurality of tasks of the booting process includes selection information of the plurality of tasks of the booting process, comprising a priority field, at least one dependency field, a lock field, and a status field;

categorize, based on the selection information for the plurality of tasks of the booting process, the accessed TDC to generate;

an independent task chart (ITC) comprising a set of independent tasks independent of any other tasks, and

a dependent task chart (DTC) comprising a set of dependent tasks having at least one dependency on another task, wherein the DTC is further categorized into;

a dependent task chart 1 (DTC 1) comprising a first set of dependent tasks from the DTC having at least one dependency on at least one task selected from the set of independent tasks of the ITC, and

a dependent task chart 2 (DTC 2) comprising a second set of dependent tasks from the DTC having at least one dependency on the at least one DTC 1 task selected from the first set of dependent tasks of the DTC 1 or at least one task selected from the second set of dependent tasks of the DTC 2,

execute the set of tasks from the ITC by selecting at least one ITC task from the ITC based on the selection information, execute the at least one ITC task, updating a status bit register for completion of the at least one ITC task, and check for at least one unexecuted task from the ITC, thereby

when all tasks in the set of independent tasks of the ITC are completed, select at least one DTC 1 task from the DTC 1 based on the selection information, execute the at least one DTC 1 task, updating the status bit register for completion of the at least one DTC 1 task, and check for at least one unexecuted task from the DTC 1, and thereby

when all tasks in the first set of dependent tasks of the DTC 1 are completed, select at least one DTC 2 task from the DTC 2 based on the selection information, execute the at least one DTC 2 task based on the at least one dependency on at least one task selected from the first set of dependent tasks of the DTC 1 or at least one task selected from the second set of dependent tasks of the DTC 2, updating the status bit register for completion of the at least one DTC 2 task, and check for at least one unexecuted task from the DTC 2.

12. The computer system as claimed in claim 11, wherein the selection information comprises the priority field representing a priority of the plurality of tasks, and the at least one task is selected based on the selection information arranged in an ascending order of the priority by the multiple CPUs.

13. The computer system as claimed in claim 11, wherein the selection information comprises at least one of the dependency field, the lock field, or the status field.

14. The computer system as claimed in claim 11, wherein the TDC is categorized based on the dependency of the plurality of tasks.

15. The computer system as claimed in claim 11, wherein the ITC is arranged and executed in an ascending order of the priority of the set of independent tasks.

16. The computer system as claimed in claim 11, wherein the DTC is arranged in an ascending order of the priority of the set of dependent tasks and the at least one dependency on the other task.

17. The computer system as claimed in claim 16, wherein the other task is at least one task selected from the set of independent tasks of the ITC, from the first set of dependent tasks of the DTC 1, or from the second set of dependent tasks of the DTC 2.

18. The computer system as claimed in claim 11, wherein the set of independent tasks from the ITC are executed first, the first set of dependent tasks from the DTC 1 are executed after the execution of the set of independent tasks from the ITC, and the second set of dependent tasks from the DTC 2 are executed after the execution of the first set of dependent tasks from the DTC1.

19. The computer system as claimed in claim 11, wherein the second set of dependent tasks from the DTC 2 are executed based on the dependencies of the second set of dependent tasks.

20. The computer system as claimed in claim 11, wherein the status bit register is maintained for completion of each task and to check the at least one unexecuted task, wherein the status bit register is stored in the memory.