| |||
Home > big.LITTLE Technology > Software execution models in big.LITTLE > Global Task Scheduling |
Through the development of big.LITTLE technology, ARM has evolved the software models starting with various migration models through to Global Task Scheduling (GTS) that forms the basis for all future development in big.LITTLE technology. The ARM implementation of GTS is called big.LITTLE Multiprocessing (MP).
In this model the operating system task scheduler is aware of the differences in compute capacity between big and LITTLE cores. Using statistical data, the scheduler tracks the performance requirement for each individual software thread, and uses that information to decide which type of core to use for each. This model can work on a big.LITTLE system with any number of cores in any cluster. This is shown in Figure 16.3. This approach has a number of advantages over the migration models, such as:
The system can have different numbers of big and LITTLE cores.
Unlike the migration model, any number of cores can be active at any one time. This can increase the maximum compute capacity available if peak performance is required.
It is possible to isolate the big cluster for the exclusive use of intensive threads, while light threads run on the LITTLE cluster. This enables heavy compute tasks to complete faster, as there are no additional background threads.
It is possible to target interrupts individually to big or LITTLE cores.