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A Novel Method for Enabling FPGA Context-Switch

Auteur(s) : A. Bourge, O. Muller, F. Rousseau

Doc. Source: ACM/SIGDA International Symposium on Field-Programmable Gate Arrays

Publisher : ACM IEEE

Pages : 261

Modern FPGAs provide great computational power, flexible resources and a versatile environment. Managing to obtain the best of these three worlds is rather complicated given the actual design flows. Our work focus on enabling task multiplexing, as part of a more flexible FPGA usage. Task multiplexing in FPGAs raises indeed a lot of questions. Multiplexing the usage of a reconfigurable fabric is leading to a better utilization of its surface because it offers to share its resources not only in space (number of slices allocated to a task) but also in time (tasks are allowed in time slots). The base mechanism known as context-switch consists in removing a task after its allowed time slot has passed. The first step toward efficiently multiplex tasks in a reconfigurable fabric is to decide when this removal will have the least possible impact on the system. This poster presents our preliminary results concerning what we consider as necessary in order to enable such a feature. Our work focus on finding automatically the best instants of the task execution in order to effectively remove a running task from the FPGA, taking into account the time needed to extract a relevant context necessary to restart it later. This instant selection is performed at a high level of abstraction, enabling us to make choices with an accurate knowledge of the task nature and specificities. The second part of this poster presents the entire mechanism which makes use of the previously selected slots in order to switch between tasks.