Efficient reboot of an operating system

Patent metadata

Field	Value
Publication number	US-2017372075-A1
Application number	US-201615191438-A
Country	US
Kind code	A1
Filing date	Jun 23, 2016
Priority date	Jun 23, 2016
Publication date	Dec 28, 2017
Grant date	—

Abstract

A computer system is rebooted upon crash without running platform firmware and without retrieving all of the modules included in a boot image from an external source and reloading them into system memory. The reboot process includes the steps of stopping and resetting all of the processing units, except one of the processing units that detected the crash event, selecting the one processing unit to execute a reboot operation, and executing the reboot operation to reboot the computer system.

First claim

What is claimed is:

1 . A method for rebooting system software for a computer system upon crash of the computer system, the method comprising:
stopping and resetting all processing units of the computer system, except one of the processing units that detected the crash event; selecting the one processing unit to execute a reboot operation; and executing the reboot operation on the selected processing unit to reboot the system software, wherein the reboot operation does not run platform firmware of the computer system and causes a designated one of the processing units to execute a boot loader module for the system software, the execution of which loads a kernel module of the system software for execution and transfers execution control thereto.

2 . The method of claim 1 , wherein the reboot operation includes the step of:
reloading a boot loader module for the system software into the system memory prior to causing the designated processing unit to execute the boot loader module.

3 . The method of claim 1 , wherein the reboot operation includes the steps of:
confirming that a first module of the system software that resided in memory at the time of the crash, is corrupted; confirming that a second module of the system software that resided in memory at the time of the crash, is not corrupted; and reloading the first module of the system software but not the second module of the system software prior to completion of the reboot operation.

4 . The method of claim 3 , wherein the step of confirming a module includes:
verifying that a checksum or hash of the module matches a stored checksum or hash for the module.

5 . The method of claim 3 , wherein a boot image that includes the first and second modules of the system software is resident in memory at the time of the crash and the entire boot image is not retrieved from an external source and reloaded into the system memory between the time of the crash and the passing of control to the kernel module of the system software.

6 . The method of claim 1 , further comprising:
prior to executing the reboot operation, shutting down pending I/O operations.

7 . The method of claim 6 , wherein shutting down the pending I/O operations includes resetting all I/O device controllers to their default state.

8 . The method of claim 1 , wherein causing a dedicated one of the processing units to execute the second level boot loader includes sending an inter-processor interrupt to the dedicated one of the processing units.

9 . The method of claim 1 , wherein the system software is an operating system or a hypervisor.

10 . A non-transitory computer readable medium comprising instructions for causing a computer system to carry out a method for rebooting system software for the computer system upon crash of the computer system, the method including the steps of:
stopping and resetting all processing units of the computer system, except one of the processing units that detected the crash event; and selecting the one processing unit to execute a reboot operation; and executing the reboot operation on the selected processing unit to reboot the system software, wherein the reboot operation does not run platform firmware of the computer system and causes a designated one of the processing units to execute a boot loader module for the system software, the execution of which loads a kernel module of the system software for execution and transfers execution control thereto.

11 . The non-transitory computer readable medium of claim 10 , wherein the reboot operation includes the step of:
reloading a boot loader module for the system software into the system memory prior to causing the designated processing unit to execute the boot loader module.

12 . The non-transitory computer readable medium of claim 10 , wherein the reboot operation includes the steps of:
confirming that a first module of the system software that resided in memory at the time of the crash, is corrupted; confirming that a second module of the system software that resided in memory at the time of the crash, is not corrupted; and reloading the first module of the system software but not the second module of the system software prior to completion of the reboot operation.

13 . The non-transitory computer readable medium of claim 12 , wherein the step of confirming a module includes:
verifying that a checksum or hash of the module matches a stored checksum or hash respectively for the module.

14 . The non-transitory computer readable medium of claim 12 , wherein a boot image that includes the first and second modules of the system software is resident in memory at the time of the crash and the entire boot image is not retrieved from an external source and reloaded into the system memory between the time of the crash and the passing of control to the kernel module of the system software.

15 . The non-transitory computer readable medium of claim 10 , wherein the method further includes:
prior to executing the reboot operation, shutting down pending I/O operations.

16 . The non-transitory computer readable medium of claim 15 , wherein shutting down the pending I/O operations includes resetting all I/O device controllers to their default state.

17 . The non-transitory computer readable medium of claim 10 , wherein causing a dedicated one of the processing units to execute the second level boot loader includes sending an inter-processor interrupt to the dedicated one of the processing units.

18 . A computer system comprising:
a system memory containing a boot image that includes system software modules that were loaded during booting of system software, and a boot loader for the system software; and one or more processing units, wherein at least one processing unit is configured to carry out a method for rebooting system software for the computer system upon crash of the computer system, the method including the steps of: stopping and resetting all of the processing units, except one of the processing units that detected the crash event; and selecting the one processing unit to execute a reboot operation; and executing the reboot operation to reboot the system software, wherein the reboot operation does not run platform firmware of the computer system and causes a designated one of the processing units to execute a boot loader module for the system software, the execution of which loads a kernel module of the system software for execution and transfers execution control thereto.

19 . The computer system of claim 18 , wherein the reboot operation includes the step of:
reloading a boot loader module for the system software into the system memory prior to causing the designated processing unit to execute the boot loader module.

20 . The computer system of claim 18 , wherein the reboot operation includes the steps of:
confirming that a first module of the system software that resided in memory at the time of the crash, is corrupted; confirming that a second module of the system software that resided in memory at the time of the crash, is not corrupted; and reloading the first module of the system software but not the second module of the system software prior to completion of the reboot operation.

Assignees

• Vmware Inc

Inventors

• Lu Xunjia
• Deguillard Xavier
• Gunti Mukund
• Sekhar Vishnu

Classifications

• G06F9/442

  Shutdown · CPC title

• G06F9/4403

  Processor initialisation · CPC title

• G06F21/575 Primary

  Secure boot · CPC title

• G06F1/24

  Resetting means · CPC title

• G06F9/4406

  Loading of operating system · CPC title