Reduced data transfer during processor context switching

A system comprising:

• one or more processors;
• local memory for each of the processors;
• system memory shared by all of the processors;
• a plurality of processes executed by the processors in accordance with a time-sharing, microtasking programming model, such that a process executed by one of the processors and data needed and used by the process have a size less than the local memory of the processor;
• and,
• a scheduling mechanism to schedule execution of the processes on the processors,
• such that switching execution on a processor from a first process to a second process running within a same processor core of the processor results in transfer of all of the local memory of the processor as the data associated with the first process to the system memory, except for a first, second and third portion of the local memory that does not require transfer for proper saving of the data associated with the first process to the system memory,
• wherein the first portion is determined as the portion of the local memory as always unused by the first process during execution of the first process by the processor,
• wherein the second portion is determined as the portion of the local memory as already being identical to a corresponding portion of the system memory such that transfer is not required, and
• wherein the third portion is determined as the third portion of the local memory as being shared between the first and the second process.

A computer program product comprising a storage device storing computer-readable code that when executed by a processor causes the processor to:

• switch context of the processor having local memory from a first process to a second process running within a same processor core of the processor, including transferring all of the local memory as the data associated with the first process to system memory, except for a first, second, and third portion of the local memory that is not required to be saved to the system memory for proper saving of the data associated with the first process to the system memory,
• wherein the first portion is determined as the portion of the local memory as always unused by the first process during execution of the first process by the processor,
• wherein the second portion is determined as the portion of the local memory as already being identical to a corresponding portion of the system memory such that transfer is not required, and
• wherein the third portion is determined as the third portion of the local memory as being shared between the first and the second process.