On Thu, Apr 19, 2007 at 05:20:53PM -0700, Michael K. Edwards wrote: > Embedded systems are already in 2007, and the mainline Linux scheduler > frankly sucks on them, because it thinks it's back in the 1960's with > a fixed supply and captive demand, pissing away "CPU bandwidth" as > waste heat. Not to say it's an easy problem; even academics with a > dozen publications in this area don't seem to be able to model energy > usage to the nearest big O, let alone design a stable economic > dispatch engine. But it helps to acknowledge what the problem is: > even in a 1960's raised-floor screaming-air-conditioners > screw-the-power-bill machine room, you can't actually run a > half-decent CPU flat out any more without burning it to a crisp. > stupid. What's your excuse? ;-)
It's now possible to QoS significant parts of the kernel since we now have a deadline mechanism in place. In the original 2.4 kernel, TimeSys's irq-thread allowed for the processing of skbuffs in a thread under a CPU reservation run category which was use to provide QoS I believe. This basic mechanish can now be generalized to many place in the kernel and put it under scheduler control. It's just a matter of who and when somebody is going take on this task. bill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
