Interesting article, explains some of the tradeoffs that OSs make in scheduling.
OS scheduler optimizations are difficult. Often what makes the desktop nice and snappy makes background stuff slower. There are always trade-offs. Its also allows vendors to sell expensive versions of linux with different schedulers (redhat mrg...cough..) The Completely Fair Scheduler with its tree of process seems to work quite well though.
It seems like they were trying to optimize for specific hardware (the link to "scheduling domains" was interesting) when cpu swapping. (2 cores vs 2 sepearate cpus...)
good intentions, but..
Sometimes its useful to let users explicitly control which cpus processes can run on (process affinity). On the HPUX variant we used they let us set up groups of cpus and then map processes run on those cpu sets. you could also select scheduling of each process startup. It was a pain to get things running, but in the end it worked great. Manually selecting the wrong scheduler and process priority could result in some processes running terribly however.
OS scheduler optimizations are difficult. Often what makes the desktop nice and snappy makes background stuff slower. There are always trade-offs. Its also allows vendors to sell expensive versions of linux with different schedulers (redhat mrg...cough..) The Completely Fair Scheduler with its tree of process seems to work quite well though.
It seems like they were trying to optimize for specific hardware (the link to "scheduling domains" was interesting) when cpu swapping. (2 cores vs 2 sepearate cpus...) good intentions, but..
Sometimes its useful to let users explicitly control which cpus processes can run on (process affinity). On the HPUX variant we used they let us set up groups of cpus and then map processes run on those cpu sets. you could also select scheduling of each process startup. It was a pain to get things running, but in the end it worked great. Manually selecting the wrong scheduler and process priority could result in some processes running terribly however.