International Business Machines Corporation

Luke Mathew Browning

Khalid Filali-Adib

Frederic Barrat

Philippe Bergheaud

Mallesh K Lepakshaiah

Kavitha Ramalingam

Larry Bert Brenner

John Mark McConaughy

David W Sheffield

Stephen Bailey Peckham

Sungjin Yook

Christophe Lombard

Laurent Dufour

Donald Ray Stence

Guy Menanteau

Randal Craig Swanberg

Perinkulam I Ganesh

Mechanisms are provided for performing a live update of an operating system. The mechanisms receive an update to an operating system and clone a root volume group associated with an operating system instance executing in a first logical partition of the data processing system to generate a cloned root volume group. The mechanisms apply the update to the cloned root volume group to generate an updated and cloned root volume group and boot a second logical partition of the data processing system using the updated and cloned root volume group. Moreover, the mechanisms migrate application instances and application data to the second logical partition.

Live operating system update mechanisms

A method, system and computer-usable medium are disclosed for managing virtual processor operations. A dynamic loader receives a request to initiate the creation of a new process, followed by a virtual processor being assigned to an isolated execution environment. The dynamic loader then initiates the creation of the new process by mapping kernel data associated with the virtual processor into the address space of the process. The dynamic loader completes the creation of the new process, and its execution is initiated within the isolated execution environment.

Initiating software applications requiring different processor architectures in respective isolated execution environment of an operating system

Some embodiments of the inventive subject matter are directed to detecting a request, from an application for a first instance of an operating system (OS) running a first version of the OS, to access a symbol via a special file that accesses kernel memory directly. A second instance of the OS, which manages the first OS, receives the request. The second instance of the OS runs a second version of the OS and includes a kernel shared between the first and second instances of the OS. Some embodiments are further directed to detecting data associated with the symbol, where the data is in a first data format that is compatible with the second version of the OS but incompatible with the first version of the OS and reformatting the data from the first data format to a second data format compatible with the second version of the OS.

Abstracting special file interfaces to concurrently support multiple operating system levels

Some examples include a system, a computer program product, an apparatus, and the like, configured to perform operations to access, in response to a request by a first instance of an operating system, data stored in a memory of a kernel of a second instance of the operating system. The operations are further to determine whether the data stored in the memory of the kernel of the second instance of the operating system is in a data format that is compatible with the first instance of the operating system. The operations are further to provide the data in the data format that is compatible with the first instance of the operating system. For instance, in some examples, the operations are to determine that the data is in a format incompatible with the first instance of the operating system, and reformat the data in the data format compatible with the first instance of the operating system.

Some embodiments of the inventive subject matter are directed to detecting a request to access a symbol via a special file that accesses kernel memory directly. The request can come from an application from a first instance of an operating system (OS) running a first version of the OS. A second instance of the OS, which manages the first OS, receives the request. The second instance of the OS includes a kernel shared between the first and second instances of the OS. The second instance of the OS runs a second version of the OS. Some embodiments are further directed to detecting data associated with the symbol, where the data is in a first data format that is compatible with the second version of the OS but is incompatible with the first version of the OS. Some embodiments are further directed to reformatting the data from the first data format to a second data format compatible with the second version of the OS.

A system and method is provided for using a kernel exit routine, performed when a parent process exits, to efficiently remove zombie child processes. The kernel exit routine also re-parents active child processes to a standard system process, such as the init process. When the kernel exit routine re-parents the active child process to the init process, the child process is flagged indicating that the child's original parent process has already exited. A kernel routine, such as the swapper process, periodically cleans up flagged processes that have exited. In this manner, although active child processes are still re-parented to init, the init process is no longer burdened with the task of waiting on such processes when they exit.

System and method to improve harvesting of zombie processes in an operating system

Apparatus and methods are provided for selecting a thread to dispatch in a multiple processor system having a global run queue associated with each multiple processor node and having a local run queue associated with each processor. If the global run queue and the local run queue associated with the processor performing the dispatch are both not empty, then the highest priority queue is selected for dispatch, as determined by examining the queues without obtaining a lock. If one of the two queues is empty and the other queue is not empty, then the non-empty queue is selected for dispatch. If the global queue is selected for dispatch but a lock on the global queue cannot be obtained immediately, then the local queue is selected for dispatch. If both queues are empty, then an idle load balancing operation is performed. Local run queues for other processors at the same node are examining without obtaining a lock. If a candidate thread is found that satisfies a set of shift conditions, and if a lock can be obtained on both the non-local run queue and the candidate thread, then the thread is shifted for dispatch by the processor that is about to become idle.

Growing community of inventors

Austin, TX, United States of America

Luke Mathew Browning