OS X Snow Leopard to Use ULE Scheduler?


Ever since Steve Jobs first unveiled the next version of OS X, dubbed “Snow Leopard,” the internet has been abuzz with excitement and wondering about the supposed “evolutionary” qualities of OS X 10.6. One of the most-hyped improvements is the promised revamp of the SMP capabilities of OS X, with a “breakthrough” in SMP performance.

The codename for the technology behind the SMP improvements in OS X Snow Leopard has been named “Grand Central,” which Apple describes best:

“Grand Central,” a new set of technologies built into Snow Leopard, brings unrivaled support for multicore systems to Mac OS X. More cores, not faster clock speeds, drive performance increases in today’s processors. Grand Central takes full advantage by making all of Mac OS X multicore aware and optimizing it for allocating tasks across multiple cores and processors. Grand Central also makes it much easier for developers to create programs that squeeze every last drop of power from multicore systems.

Our guess is that these SMP “breakthroughs” are going to be delivered in two blows:

  1. Improvements to the OS X kernel intended to boost multi-threading & multi-tasking performance and better-distribute the loads across multiple CPU cores more intelligently.
  2. Provide an SDK (perhaps as improvements to XCode) that allows developers to more-easily write multi-threaded code, handle forking, and provide load-balancing features on a per-core basis.

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