International Business Machines Corporation

Joseph C Kantz

David Andrew Rice

Paul D DiNicola

Omar M Rahim

Edward M Ruddick

Susan D Wright

Abraham Mammen

An efficient polling technique to attain improved system performance preserves the concept of polling, but instead of polling across system buses to the device, a poll is made within the processor's cache structure, which is typically internal to the processor complex or attached on a local isolated bus. The polling status location is mapped in the cachable address space of the processor. Hence, the polling occurs to a normal cachable location. When the device completes its task, it signals to the polling loop by invalidating the cache line corresponding to the poll location. The next time software tries to read the status value, the processor misses in its cache and automatically reloads the updated status value from the device. This causes the polling loop to exit and normal processing continues. The only bus traffic that results is that which is issued by the device to signal cache line invalidation and a subsequent processor initiated cache line reload. Hence, the bus is totally available for all agents while the processor is within the polling loop.

Efficient polling technique using cache coherent protocol

In a graphics subsystem, a highly interactive two-dimensional (2D) data stream and a computationally intensive three-dimensional (3D) data stream are processed concurrently in such a manner that processing of the 2D data stream is not held up by processing of the 3D data stream. A 3D geometry subsystem having a parallel pipeline architecture is used to process the 3D data stream, while a 2D subsystem concurrently processed the 2D data stream in parallel with the 3D subsystem. A reordering device couples the processed 2D and 3D data streams to a common raster subsystem. The reordering device, which contains an internal buffer, reorders any order-dependent elements of the 3D data stream appearing at the output of the 3D geometry subsystem in an order different from the order in which they were supplied to the input end. The reordering device prioritizes the 2D data stream relative to the 3D data stream so that elements of the 2D data stream arriving from the 2D subsystem are passed to the raster subsystem almost immediately, without having to wait for elements of the 3D data stream.

Method and apparatus for processing two graphics data streams in parallel

The data processing system includes processing nodes and a graphics display device for processing a graphics data stream. The data processing system partitions a graphics data stream into a data segments or work groups for processing by the processing nodes. Next, the data segments are distributed for processing to the processing nodes. In response to receiving a data segment at a processing node, the data segment is processed to produce a processed data segment. The processed data segments are recombined into a processed graphics data stream. This processed graphics data stream is coupled to the graphics display device.

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Saugerties, NY, United States of America

Joseph C Kantz