Quoting Morten Rasmussen (2015-10-15 09:10:44)
On Thu, Oct 15, 2015 at 10:24:27AM +0100, Patrick Bellasi wrote:
Actually, I think it could make sense from a power standpoint.
For example, if you are under a thermal constraint but still want to progress with your workload there are only two possibilities: a) throttle an energy-efficient OPP b) switch to a low-power OPP, even if less energy-efficient i.e. reduced the F without lowering the V
I have heard the same argument several times from thermal management people. Despite their lower energy efficiency they still rely on their lower power to stay within the thermal budget.
I'm personally more for the first solution and a suitable usage of bandwidth control could be just enough to provide such a solution.
Agreed, using inefficient OPPs is not really desirable, but is the only option available at the moment. I think that ideally, we should have hardware implemented idle-injection (throttling) instead and let the thermal framework specify the duty cycle. Throttling through software could work, but it isn't feasible to do tricks like aligning the throttling across all cpus in a cluster to enter a deeper idle-state and make the throttling even more efficient.
You mean something like this?
git://git.kernel.org/pub/scm/linux/kernel/git/mturquette/linux.git idleforce
Regards, Mike