International Business Machines Corporation

Daniel Anson Heffley

Cheng-Chung Song

Chiahong Chen

Wenjeng Ko

Itzhack Goldberg

Stephen LaRoux Blinick

Scott A Brewer

Radha K Ramachandran

Jimmie Lee Brundidge

A sleep function capable of putting a fixed high-priority thread to sleep within a time-window is disclosed. After a sleep request has been made by a fixed high-priority thread via the sleep function, a determination is made whether or not the fixed high-priority thread is awoken before a requested sleep duration under the sleep request. If the fixed high-priority thread is awoken before the requested sleep duration, the number of tasks for the fixed high-priority thread to perform is increased in order to delay the start sleep time of the fixed high-priority thread from a point within a first time-window in which the sleep request was made to an end boundary of the first time-window.

Method and apparatus for adjusting sleep time of fixed high-priority threads

A method, apparatus and program storage device for providing light weight system calls to improve user mode performance is disclosed. A range of system call code for the light weight system calls is provided in a system call table. The light weight system calls skip the code for saving and restore processor context.

Method, apparatus and program storage device for providing light weight system calls to improve user mode performance

A method, apparatus and program storage device for providing a no context switch attribute that allows a user mode thread to become a near interrupt disabled priority is disclosed. A thread includes a no context switch attribute. Control of a thread based on the no context switch attribute is much more efficient than the real-time priority because the no context switch attribute bypasses the overhead of scheduling. Moreover, the no context switch attribute may be used to detect whether a thread performs any undesirable operations that can cause the thread to become suspended while in a critical section. The no context switch attribute is configurable to indicate whether execution of the thread can be suspended.

Handling of user mode thread using no context switch attribute to designate near interrupt disabled priority status

A method, apparatus and program storage device for performing fault tolerant code upgrade on a fault tolerant system by determining when functional code reaches a desired state before resuming an upgrade. A concurrent code-load to a plurality of storage controllers of a storage system is initiated. A role transition is detected. The storage system determines when the storage system returns to a desired state. The code-load is resumed when the storage system returns to the desired state.

Method, apparatus and program storage device for performing fault tolerant code upgrade on a fault tolerant system by determining when functional code reaches a desired state before resuming an upgrade

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Tucson, AZ, United States of America

Daniel Anson Heffley