On Wednesday 18 June 2008, Woodruff, Richard wrote: > > > > As measured using ETM trace this drops my reprogramming penalty from > > almost 60% CPU load down to 15% during high interrupt rate. If you like > > I can send traces to show this.
More than doubling the available-for-real-use CPU time! Impressive. I'd imagine that many systems using reprogrammable 32K timers for scheduling could win from such a patch, although not necessarily quite so visibly as on this ARM unless their CPU clocks were also in the 500+ MHz range. Seems like a "law of unintended consequences" here. Use a 32K timer since it takes less power than a multi-MHz one, and so the faster clocks can be gated off more comprehensively (in hardware) to give more power savings. Then throw NO_HZ on top to get one more increment of power savings ... whoops, it was assuming that it was dirt cheap to reprogram timers, major badness! - Dave -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
