On 12/28/2011 12:03 PM, Somebody in the thread at some point said:
2011/12/23 Bernhard Rosenkränzerbernhard.rosenkranzer@linaro.org:
On 22 December 2011 18:42, Zach Pfefferzach.pfeffer@linaro.org wrote:
I disagree. I've spoken with many who would like to base products off of this. At the end of the day the kernel doesn't actually have much of a difference - in fact newer kernels have tended to slow things down and make things less stable.
I don't think that's the new kernels' fault - it's more likely because we've been enabling more debug features.
That's true. We haven't done a thorough breakdown of the impacts of each modification we've made, apart from the monthly benchmarks. My main point was that the kernel is only one component of many in Android and that upgrades to it may have either positive or negative effects on the user, but those effects tend to be less pronounced than compiler improvements, hardware acceleration, etc. Even on the PM front. You can try to do as much as you want in the kernel, but your LCD still eats 50% of your battery, WiFI and 3G eat 25% - so you're working to optimize the rest of the 25%.
That's assuming kernel pm is already there and doing its job. If dvfs and the other major kernel pm elements are absent, in fact your CPU is pulling more power than the rest of a typical offhook smartphone put together all the time.
So it's more accurate to look at it that kernel pm is reducing the cpu power share from 125% to 25%... highly critical for battery case.
-Andy