Chapter 19. 13h30 - Chip Multi Processing(CMP) aware Linux Kernel Scheduler

Chip Multi Processing(CMP) aware Linux Kernel Scheduler

Suresh Siddha

Suresh, from Intel, gave an interesting talk about the new crop of hyper-threaded CPUs, multi-core CPUs, and multi-CPU designs (and various combinations thereof) that are now available, pointing out how the Linux scheduler could be coded a bit smarter to help distribute the load equally among all the available processing resources. He talked about how some current schedulers think that it makes more sense to place all the processing on the fewest number of chips available since it might be possible to put the un-used ones to sleep, but the fact is that if the processing resources share the same power-plane (i.e. on one die) it's not possible to put one core to sleep while the other one continues to work.

His resource balancing scheme doesn't account for the savings that might come from shared resources such as the memory controller or various levels of cache. His talk only dealt with maximizing processing resources.