On Fri, 2010-08-27 at 01:10 -0700, skannan@xxxxxxxxxxxxxx wrote: > Ignoring other details for now, the biggest problem with throughput/KBps > units is that PM QoS can't handle it well in its current state. For KBps > the requests should be added together before it's "enforced". Just picking > the maximum won't work optimally. > > Another problem with using KBps is that the available throughput is going > to vary depending on the CPU frequency since the CPU running at a higher > freq is going to use more bandwidth/throughput than the same CPU running > at a lower freq. > > A KHz unit will side step both problems. It's not the most ideal in theory > but it's simple and gets the job done since, in our case, there aren't > very many fine grained levels of system bus frequencies (and corresponding > throughputs). > > I understand that other architectures might have different practical > constraints and abilities and I didn't want to impose the KHz limitation > on them. That's the reason I proposed a parameter whose units is defined > by the "enforcer". Like Mark said, unit-less constraints are impossible to use correctly. What if a driver moves from one platform to another? Also, the KHz thing you propose simply doesn't make sense, given a fixed bus width, KBs and KHz have a fixed ratio, and thus you get the exact same problem you initially had and refused to fix. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
